/tmp/build/foma/foma-0.10.0+g279~a2d32b38/constructions.c

Bug Summary

File:	constructions.c
Warning:	line 677, column 17 Access to field 'mainloop' results in a dereference of a null pointer (loaded from variable 'iptr')
Annotated Source Code

Press '?' to see keyboard shortcuts
Show analyzer invocation
clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name constructions.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/tmp/build/foma/foma-0.10.0+g279~a2d32b38 -resource-dir /usr/lib/llvm-16/lib/clang/16 -D _GNU_SOURCE -D foma_shared_EXPORTS -I /tmp/build/foma/foma-0.10.0+g279~a2d32b38 -internal-isystem /usr/lib/llvm-16/lib/clang/16/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -Wno-missing-field-initializers -Wno-deprecated -Wno-unused-parameter -std=c18 -fdebug-compilation-dir=/tmp/build/foma/foma-0.10.0+g279~a2d32b38 -ferror-limit 19 -fvisibility=hidden -fgnuc-version=4.2.1 -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/build/foma/scan-build/2024-09-11-155945-2678-1 -x c /tmp/build/foma/foma-0.10.0+g279~a2d32b38/constructions.c
1/*   Foma: a finite-state toolkit and library.                                 */
2/*   Copyright © 2008-2021 Mans Hulden                                         */

4/*   This file is part of foma.                                                */

6/*   Licensed under the Apache License, Version 2.0 (the "License");           */
7/*   you may not use this file except in compliance with the License.          */
8/*   You may obtain a copy of the License at                                   */

10/*      http://www.apache.org/licenses/LICENSE-2.0                             */

12/*   Unless required by applicable law or agreed to in writing, software       */
13/*   distributed under the License is distributed on an "AS IS" BASIS,         */
14/*   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  */
15/*   See the License for the specific language governing permissions and       */
16/*   limitations under the License.                                            */

18#include <stdio.h>
19#include <stdlib.h>
20#include <string.h>
21#include "foma.h"

23#define KLEENE_STAR0 0
24#define KLEENE_PLUS1 1
25#define OPTIONALITY2 2

27#define COMPLEMENT0 0
28#define COMPLETE1 1

30#define STACK_3_PUSH(a,b,c)int_stack_push(a); int_stack_push(b); int_stack_push(c); int_stack_push(a); int_stack_push(b); int_stack_push(c);
31#define STACK_2_PUSH(a,b)int_stack_push(a); int_stack_push(b); int_stack_push(a); int_stack_push(b);

33struct mergesigma {
char *symbol;
unsigned char presence; /* 1 = in net 1, 2 = in net 2, 3 = in both */
int number;
struct mergesigma *next;
38};

40int sort_cmp(const void *a, const void *b) {
return (((const struct fsm_state *)a)->state_no - ((const struct fsm_state *)b)->state_no);
42}

44int add_fsm_arc(struct fsm_state *fsm, int offset, int state_no, int in, int out, int target, int final_state, int start_state);

46struct fsm *fsm_kleene_closure(struct fsm *net, int optionality);

48struct fsm *fsm_kleene_star(struct fsm *net) {
return (fsm_kleene_closure(net, KLEENE_STAR0));
50}

52struct fsm *fsm_kleene_plus(struct fsm *net) {
return (fsm_kleene_closure(net, KLEENE_PLUS1));
54}

56struct fsm *fsm_optionality(struct fsm *net) {
return (fsm_kleene_closure(net, OPTIONALITY2));
58}

60struct fsm *fsm_escape(char *symbol) {
return(fsm_symbol(symbol+1));
62}

64/* Convert a multicharacter-string-containing machine */
65/* to the equivalent "letter" machine where all arcs  */
66/* are single utf8 letters.                           */

68struct fsm *fsm_letter_machine(struct fsm *net) {

  struct fsm *outnet;
  struct fsm_read_handle *inh;
  struct fsm_construct_handle *outh;
  int i, steps, source, target, addstate, innum, outnum, inlen, outlen;
  char *in, *out, *currin, *currout, tmpin[128], tmpout[128];

  inh = fsm_read_init(fsm_minimize(net));
  outh = fsm_construct_init("name");
  addstate = net->statecount;

  while (fsm_get_next_arc(inh)) {
      in = fsm_get_arc_in(inh);
out = fsm_get_arc_out(inh);
innum = fsm_get_arc_num_in(inh);
outnum = fsm_get_arc_num_out(inh);
source = fsm_get_arc_source(inh);
target = fsm_get_arc_target(inh);

if (((innum > IDENTITY2) && utf8strlen(in) > 1) || ((outnum > IDENTITY2) && utf8strlen(out) > 1)) {
   inlen = innum <= IDENTITY2 ? 1 : utf8strlen(in);
   outlen = outnum <= IDENTITY2 ? 1 : utf8strlen(out);
   steps = inlen > outlen ? inlen : outlen;

   target = addstate;
   for (i = 0; i < steps; i++) {
if (innum <= IDENTITY2 || inlen < 1) {
    if (inlen < 1)
	currin = "@_EPSILON_SYMBOL_@";
    else
	currin = in;
} else {
    strncpy(tmpin, in, utf8skip(in)+1);
    *(tmpin+utf8skip(in)+1) = '\0';
    currin = tmpin;
    inlen--;
    in = in+utf8skip(in)+1;
}
if (outnum <= IDENTITY2 || outlen < 1) {
    if (outlen < 1)
	currout = "@_EPSILON_SYMBOL_@";
    else
	currout = out;
} else {
    strncpy(tmpout, out, utf8skip(in)+1);
    *(tmpout+utf8skip(out)+1) = '\0';
    currout = tmpout;
    out = out+utf8skip(out)+1;
    outlen--;
}
if (i == 0 && steps > 1) {
    target = addstate;
    addstate++;
}
if (i > 0 && (steps-i == 1)) {
    source = addstate - 1;
    target = fsm_get_arc_target(inh);
}
if (i > 0 && (steps-i != 1)) {
    source = addstate-1;
    target = addstate;
    addstate++;
}
fsm_construct_add_arc(outh,source,target,currin,currout);
   }
} else {
   fsm_construct_add_arc(outh,source,target,in,out);
}
  }
  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(outh, i);
  }
  while ((i = fsm_get_next_initial(inh)) != -1) {
fsm_construct_set_initial(outh, i);
  }
  fsm_read_done(inh);
  outnet = fsm_construct_done(outh);
  return(outnet);
147}

149struct fsm *fsm_explode(char *symbol) {
  struct fsm *net;
  struct fsm_construct_handle *h;
  char *tempstring;
  int length, i, j, skip;

  h = fsm_construct_init("");
  fsm_construct_set_initial(h,0);

  length = strlen(symbol)-2;
  for (i=1, j=1; i <= length; i += skip, j++) {
skip = utf8skip(symbol+i)+1;
tempstring = xxstrndup(((symbol+i)),skip);
fsm_construct_add_arc(h,j-1,j,tempstring,tempstring);
free(tempstring);
  }
  fsm_construct_set_final(h, j-1);
  net = fsm_construct_done(h);
  return(net);
168}

170struct fsm *fsm_symbol(char *symbol) {
struct fsm *net;
int symbol_no;

net = fsm_create("");
fsm_update_flags(net, YES1, YES1, YES1, YES1, YES1, NO0);
if (strcmp(symbol,"@_EPSILON_SYMBOL_@")==0) {
  /* Epsilon */
  (void)sigma_add_special(EPSILON0, net->sigma);
  net->states = malloc(sizeof(struct fsm_state)*2);
  add_fsm_arc(net->states, 0, 0, -1,-1,-1,1,1);
  add_fsm_arc(net->states, 1, -1,-1,-1,-1,-1,-1);
  net->arccount = 0;
  net->statecount = 1;
  net->linecount = 1;
  net->finalcount = 1;
  net->is_deterministic = NO0;
  net->is_minimized = NO0;
  net->is_epsilon_free = NO0;
} else {
  if ((strcmp(symbol,"@_IDENTITY_SYMBOL_@") == 0)) {
    symbol_no = sigma_add_special(IDENTITY2,net->sigma);
  } else {
    symbol_no = sigma_add(symbol,net->sigma);
  }
  net->states = malloc(sizeof(struct fsm_state)*3);
  add_fsm_arc(net->states, 0, 0, symbol_no, symbol_no, 1, 0, 1);
  add_fsm_arc(net->states, 1, 1, -1, -1, -1, 1, 0);
  add_fsm_arc(net->states, 2, -1, -1, -1, -1, -1, -1);
  net->arity = 1;
  net->pathcount = 1;
  net->arccount = 1;
  net->statecount = 2;
  net->linecount = 2;
  net->finalcount = 1;
  net->arcs_sorted_in = YES1;
  net->arcs_sorted_out = YES1;
  net->is_deterministic = YES1;
  net->is_minimized = YES1;
  net->is_epsilon_free = YES1;
}
return(net);
212}

214void fsm_sort_lines(struct fsm *net) {
struct fsm_state *fsm;
fsm = net->states;
qsort(fsm, find_arccount(fsm), sizeof(struct fsm_state), sort_cmp);
218}

220void fsm_update_flags(struct fsm *net, int det, int pru, int min, int eps, int loop, int completed) {
net->is_deterministic = det;
net->is_pruned = pru;
net->is_minimized = min;
net->is_epsilon_free = eps;
net->is_loop_free = loop;
net->is_completed = completed;
net->arcs_sorted_in = NO0;
net->arcs_sorted_out = NO0;
229}

231int fsm_count_states(struct fsm_state *fsm) {
int i, temp = -1, states = 0;
for(i=0; (fsm+i)->state_no != -1; i++) {
  if (temp != (fsm+i)->state_no) {
    states++;
    temp = (fsm+i)->state_no;
  }
}
return(states);
240}

242struct state_arr {
int final;
int start;
struct fsm_state *transitions;
246};

248struct state_arr *init_state_pointers(struct fsm_state *fsm_state) {

/* Create an array for quick lookup of whether states are final, and a pointer to the first line regarding each state */

struct state_arr *state_arr;
int states, i, sold;
sold = -1;
states = fsm_count_states(fsm_state);
state_arr = malloc(sizeof(struct state_arr)*(states+1));
for (i=0; i<states; i++) {
  (state_arr+i)->final = 0;
  (state_arr+i)->start = 0;
}

for (i=0; (fsm_state+i)->state_no != -1; i++) {
  if ((fsm_state+i)->final_state == 1)
    (state_arr+((fsm_state+i)->state_no))->final = 1;
  if ((fsm_state+i)->start_state == 1)
    (state_arr+((fsm_state+i)->state_no))->start = 1;
  if ((fsm_state+i)->state_no != sold) {
    (state_arr+((fsm_state+i)->state_no))->transitions = (fsm_state+i);
    sold = (fsm_state+i)->state_no;
  }
}
return(state_arr);
273}

275/* An open addressing scheme (with linear probing) to store triplets of ints */
276/* and hashing them with an automatically increasing key at every insert     */
277/* The table is rehashed whenever occupancy reaches 0.5                      */

279struct triplethash_triplets {
  int a;
  int b;
  int c;
  int key;
284};

286struct triplethash {
  struct triplethash_triplets *triplets;
  unsigned int tablesize;
  int occupancy;
290};

292struct triplethash *triplet_hash_init() {
  struct triplethash *th;
  int i;
  th = malloc(sizeof(struct triplethash));
  th->tablesize = 128;
  th->occupancy = 0;
  th->triplets = malloc(sizeof(struct triplethash_triplets) * th->tablesize);
  for (i = 0; i < th->tablesize; i++) {
(th->triplets+i)->key = -1;
  }
  return(th);
303}

305unsigned int triplethash_hashf(int a, int b, int c) {
  return((unsigned int)(a * 7907 + b * 86028157 + c * 7919));
307}

309void triplet_hash_free(struct triplethash *th) {
  if (th != NULL((void*)0)) {
if (th->triplets != NULL((void*)0)) {
   free(th->triplets);
}
free(th);
  }
316}

318void triplet_hash_rehash(struct triplethash *th);

320void triplet_hash_insert_with_key(struct triplethash *th, int a, int b, int c, int key) {
  struct triplethash_triplets *th_table;
  unsigned int hash;
  th_table = th->triplets;
  hash = triplethash_hashf(a, b, c) % th->tablesize;
  for (;;) {
if ((th_table + hash)->key == -1) {
   (th_table + hash)->key = key;
   (th_table + hash)->a = a;
   (th_table + hash)->b = b;
   (th_table + hash)->c = c;
   break;
}
hash++;
if (hash >= th->tablesize)
   hash -= th->tablesize;
  }
337}

339int triplet_hash_insert(struct triplethash *th, int a, int b, int c) {
  struct triplethash_triplets *th_table;
  unsigned int hash;
  th_table = th->triplets;
  hash = triplethash_hashf(a,b,c) % th->tablesize;
  for (;;) {
if ((th_table + hash)->key == - 1) {
   (th_table + hash)->key = th->occupancy;
   (th_table + hash)->a = a;
   (th_table + hash)->b = b;
   (th_table + hash)->c = c;
   th->occupancy = th->occupancy + 1;
   if (th->occupancy > th->tablesize / 2) {
triplet_hash_rehash(th);
   }
   return(th->occupancy - 1);
}
hash++;
if (hash >= th->tablesize)
   hash -= th->tablesize;
  }
360}

362void triplet_hash_rehash(struct triplethash *th) {
  int i;
  unsigned int newtablesize, oldtablesize;
  struct triplethash_triplets *oldtriplets;
  newtablesize = th->tablesize * 2;
  oldtablesize = th->tablesize;
  oldtriplets = th->triplets;
  th->triplets = malloc(sizeof(struct triplethash_triplets) * newtablesize);
  th->tablesize = newtablesize;
  for (i = 0; i < newtablesize; i++) {
(th->triplets+i)->key = -1;
  }
  for (i = 0; i < oldtablesize; i++) {
if ((oldtriplets+i)-> key != -1) {
   triplet_hash_insert_with_key(th, (oldtriplets+i)->a, (oldtriplets+i)->b, (oldtriplets+i)->c, (oldtriplets+i)->key);
}
  }
  free(oldtriplets);
380}

382int triplet_hash_find(struct triplethash *th, int a, int b, int c) {
  struct triplethash_triplets *th_table;
  unsigned int hash, j;
  th_table = th->triplets;
  hash = triplethash_hashf(a, b, c) % th->tablesize;
  for (j = 0; j < th->tablesize; j++) {
if ((th_table + hash)->key == - 1)
   return -1;
if ((th_table + hash)->a == a && (th_table + hash)->b == b && (th_table + hash)->c == c) {
   return((th_table + hash)->key);
}
hash++;
if (hash >= th->tablesize)
   hash -= th->tablesize;
  }
  return -1;
398}

400struct fsm *fsm_intersect(struct fsm *net1, struct fsm *net2) {

  struct blookup {int mainloop; int target; } *array, *bptr;
  int a,b,current_state, current_start, current_final, target_number, sigma2size, mainloop;
  struct fsm_state *machine_a, *machine_b;
  struct state_arr *point_a, *point_b;
  struct fsm *new_net;
  struct triplethash *th;

  net1 = fsm_minimize(net1);
  net2 = fsm_minimize(net2);

  if (fsm_isempty(net1) || fsm_isempty(net2)) {
fsm_destroy(net1);
fsm_destroy(net2);
return(fsm_empty_set());
  }

  fsm_merge_sigma(net1, net2);

  fsm_update_flags(net1, YES1, NO0, UNK2, YES1, UNK2, UNK2);

  machine_a = net1->states;
  machine_b = net2->states;

  sigma2size = sigma_max(net2->sigma)+1;
  array = calloc(sigma2size*sigma2size, sizeof(struct blookup));
  mainloop = 0;

  /* Intersect two networks by the running-in-parallel method */
  /* new state 0 = {0,0} */

  STACK_2_PUSH(0,0)int_stack_push(0); int_stack_push(0);;

  th = triplet_hash_init();
  triplet_hash_insert(th, 0, 0, 0);

  fsm_state_init(sigma_max(net1->sigma));

  point_a = init_state_pointers(machine_a);
  point_b = init_state_pointers(machine_b);

  while (!int_stack_isempty()) {

      /* Get a pair of states to examine */

      a = int_stack_pop();
      b = int_stack_pop();

current_state = triplet_hash_find(th, a, b, 0);
      current_start = (((point_a+a)->start == 1) && ((point_b+b)->start == 1)) ? 1 : 0;
      current_final = (((point_a+a)->final == 1) && ((point_b+b)->final == 1)) ? 1 : 0;

      fsm_state_set_current_state(current_state, current_final, current_start);

      /* Create a lookup index for machine b */
      /* array[in][out] holds the target for this state and the symbol pair in:out */
      /* Also, we keep track of whether an entry is fresh by the mainloop counter */
      /* so we don't mistakenly use an old entry and don't have to clear the table */
      /* between each state pair we encounter */

      for (mainloop++, machine_b = (point_b+b)->transitions; machine_b->state_no == b; machine_b++) {
          if (machine_b->in < 0) continue;
          bptr = array+(machine_b->in*sigma2size)+machine_b->out;
          bptr->mainloop = mainloop;
          bptr->target = machine_b->target;
      }

      /* The main loop where we run the machines in parallel */
      /* We look at each transition of a in this state, and consult the index of b */
      /* we just created */

      for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a ; machine_a++) {
          if (machine_a->in < 0 || machine_a->out < 0) continue;
          bptr = array+(machine_a->in*sigma2size)+machine_a->out;

          if (bptr->mainloop != mainloop)
              continue;

          if ((target_number = triplet_hash_find(th, machine_a->target, bptr->target, 0)) == -1) {
              STACK_2_PUSH(bptr->target, machine_a->target)int_stack_push(bptr->target); int_stack_push(machine_a->
target);;
              target_number = triplet_hash_insert(th, machine_a->target, bptr->target, 0);
          }

          fsm_state_add_arc(current_state, machine_a->in, machine_a->out, target_number, current_final, current_start);

      }
      fsm_state_end_state();
  }
  new_net = fsm_create("");
  fsm_sigma_destroy(new_net->sigma);
  new_net->sigma = net1->sigma;
  net1->sigma = NULL((void*)0);
  fsm_destroy(net2);
  fsm_destroy(net1);
  fsm_state_close(new_net);
  free(point_a);
  free(point_b);
  free(array);
  triplet_hash_free(th);
  return(fsm_coaccessible(new_net));
501}

503struct fsm *fsm_compose(struct fsm *net1, struct fsm *net2) {


  /* The composition algorithm is the basic naive composition where we lazily      */
  /* take the cross-product of states P and Q and move to a new state with symbols */
  /* ain, bout if the symbols aout = bin.  Also, if aout = 0 state p goes to       */
  /* its target, while q stays.  Similarly, if bin = 0, q goes to its target       */
  /* while p stays.                                                                */

  /* We have two variants of the algorithm to avoid creating multiple paths:       */
  /* 1) Bistate composition.  In this variant, when we create a new state, we call it */
  /*    (p,q,mode) where mode = 0 or 1, depending on what kind of an arc we followed  */
  /*    to get there.  If we followed an x:y arc where x and y are both real symbols  */
  /*    we always go to mode 0, however, if we followed an 0:y arc, we go to mode 1.  */
  /*    from mode 1, we do not follow x:0 arcs.  Each (p,q,mode) is unique, and       */
  /*    from (p,q,X) we always consider the transitions from p and q.                 */
  /*    We never create arcs (x:0 0:y) yielding x:y.                                  */

  /* 2) Tristate composition. Here we always go to mode 0 with a x:y arc.             */
  /*    (x:0,0:y) yielding x:y is allowed, but only in mode 0                         */
  /*    (x:y y:z) is always allowed and results in target = mode 0                    */
  /*    0:y arcs lead to mode 2, and from there we stay in mode 2 with 0:y            */
  /*    in mode 2 we only consider 0:y and x:y arcs                                   */
  /*    x:0 arcs lead to mode 1, and from there we stay in mode 1 with x:0            */
  /*    in mode 1 we only consider x:0 and x:y arcs                                   */

  /* It seems unsettled which type of composition is better.  Tristate is similar to  */
  /* the filter transducer given in Mohri, Pereira and Riley (1996) and works well    */
  /* for cases such as [a:0 b:0 c:0 .o. 0:d 0:e 0:f], yielding the shortest path.     */
  /* However, for generic cases, bistate seems to yield smaller transducers.          */
  /* The global variable g_compose_tristate is set to OFF by default                  */

  struct outarray {
      short int symin;
      short int symout;
      int target;
      int mainloop;
  } *outarray, *iptr, *currtail;

  struct index {
      struct outarray *tail;
  } *index;

  extern int g_compose_tristate, g_flag_is_epsilon;
  int a,b,i,mainloop,current_state, current_start, current_final, target_number, ain, bin, aout, bout, asearch, max2sigma;
  struct fsm_state *machine_a, *machine_b;
  struct state_arr *point_a, *point_b;
  struct triplethash *th;
  int mode;
  _Bool *is_flag = NULL((void*)0);


  net1 = fsm_minimize(net1);
  net2 = fsm_minimize(net2);

  if (fsm_isempty(net1) || fsm_isempty(net2)) {
1
Assuming the condition is false→
2
←
Assuming the condition is false→
3
←
Taking false branch→
fsm_destroy(net1);
fsm_destroy(net2);
return(fsm_empty_set());
  }

  /* If flag-is-epsilon is on, we need to add the flag symbols    */
  /* in both networks to each other's sigma so that UNKNOWN       */
  /* or IDENTITY symbols do not match these flags, since they are */
  /* supposed to have the behavior of EPSILON                     */
  /* And we need to do this before merging the sigmas, of course  */

  if (g_flag_is_epsilon) {
4
←
Assuming 'g_flag_is_epsilon' is 0→
5
←
Taking false branch→
      struct sigma *sig1, *sig2;
      int flags1, flags2;
      flags1 = flags2 = 0;
      sig2 = net2->sigma;
      max2sigma = sigma_max(net2->sigma);
      for (sig1 = net1->sigma; sig1 != NULL((void*)0); sig1 = sig1->next) {
          if (flag_check(sig1->symbol)) {
              flags1 = 1;
              if (sigma_find(sig1->symbol, sig2) == -1) {
                  sigma_add(sig1->symbol, sig2);
              }
          }
      }

      sig1 = net1->sigma;
      for (sig2 = net2->sigma; sig2 != NULL((void*)0) ; sig2 = sig2->next) {
          if (flag_check(sig2->symbol)) {
              if (sig2->number <= max2sigma) {
                  flags2 = 1;
              }
              if (sigma_find(sig2->symbol, sig1) == -1) {
                  sigma_add(sig2->symbol, sig1);
              }
          }
      }
      sigma_sort(net2);
      sigma_sort(net1);
      if (flags1 && flags2) {
          printf("***Warning: flag-is-epsilon is ON and both networks contain flags in composition.  This may yield incorrect results.  Set flag-is-epsilon to OFF.\n");
      }
  }

  fsm_merge_sigma(net1, net2);

  if (g_flag_is_epsilon) {
6
←
Assuming 'g_flag_is_epsilon' is 0→
7
←
Taking false branch→
      /* Create lookup table for quickly checking if a symbol is a flag */
      struct sigma *sig1;
      is_flag = malloc(sizeof(_Bool)*(sigma_max(net1->sigma)+1));
      for (sig1 = net1->sigma; sig1 != NULL((void*)0); sig1=sig1->next) {
          if (flag_check(sig1->symbol)) {
              *(is_flag+(sig1->number)) = 1;
          } else {
              *(is_flag+(sig1->number)) = 0;
          }
      }
  }

  fsm_update_flags(net1, YES1, NO0, UNK2, YES1, UNK2, UNK2);

  machine_a = net1->states;
  machine_b = net2->states;

  max2sigma = sigma_max(net2->sigma);

  /* Create an index for looking up input symbols in machine b quickly */
  /* We store each machine_b->in symbol in outarray[symin][...] */
  /* the array index[symin] points to the tail of the current list in outarray */
  /* (we may have many entries for one input symbol as there may be many outputs */
  /* The field mainloop tells us whether the entry is current as we want to loop */
  /* UNKNOWN and IDENTITY are indexed as UNKNOWN because we need to find both */
  /* as they share some semantics */

  index = calloc(max2sigma+1, sizeof(struct index));
8
←
Null pointer value stored to field 'tail'→
  outarray = calloc((max2sigma+2)*(max2sigma+1), sizeof(struct outarray));

  for (i=0; i <= max2sigma; i++) {
9
←
Assuming 'i' is > 'max2sigma'→
10
←
Loop condition is false. Execution continues on line 642→
      (index+i)->tail = outarray + ((max2sigma+2)*i);
  }


  /* Mode, a, b */
  STACK_3_PUSH(0,0,0)int_stack_push(0); int_stack_push(0); int_stack_push(0);;

  th = triplet_hash_init();
  triplet_hash_insert(th, 0, 0, 0);

  fsm_state_init(sigma_max(net1->sigma));

  point_a = init_state_pointers(machine_a);
  point_b = init_state_pointers(machine_b);

  mainloop = 0;

  while (!int_stack_isempty()) {
11
←
Assuming the condition is true→
12
←
Loop condition is true.  Entering loop body→

      /* Get a pair of states to examine */

      a = int_stack_pop();
      b = int_stack_pop();
      mode = int_stack_pop();

current_state = triplet_hash_find(th, a,b,mode);
      current_start = (((point_a+a)->start == 1) && ((point_b+b)->start == 1) && (mode == 0)) ? 1 : 0;
13
←
Assuming field 'start' is not equal to 1→
      current_final = (((point_a+a)->final == 1) && ((point_b+b)->final == 1)) ? 1 : 0;
14
←
Assuming field 'final' is not equal to 1→

      fsm_state_set_current_state(current_state, current_final, current_start);

      /* Create the index for machine b in this state */
      for (mainloop++, machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {
15
←
Assuming 'b' is equal to field 'state_no'→
16
←
Loop condition is true.  Entering loop body→
          int bindex;
          /* Index b */
          bindex = (machine_b->in == IDENTITY2) ? UNKNOWN1 : machine_b->in;
17
←
Assuming field 'in' is equal to IDENTITY→
18
←
'?' condition is true→
          if (bindex18.1
'bindex' is >= 0
 < 0 || machine_b->target < 0)
19
←
Assuming field 'target' is >= 0→
20
←
Taking false branch→
              continue;

          iptr = (index+bindex)->tail;
21
←
Null pointer value stored to 'iptr'→
          if (iptr->mainloop != mainloop) {
22
←
Access to field 'mainloop' results in a dereference of a null pointer (loaded from variable 'iptr')
              iptr = (index+bindex)->tail = outarray+(bindex*(max2sigma+2));
          } else {
              iptr++;
          }
          iptr->symin = machine_b->in;
          iptr->symout = machine_b->out;
          iptr->mainloop = mainloop;
          iptr->target = machine_b->target;
          (index+bindex)->tail = iptr;
      }

      for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a ; machine_a++) {

          /* If we have the same transition from (a,b)-> some state */
          /* If we have x:y y:z trans to some state */
          aout = machine_a->out;
          ain = machine_a->in;
          /* IDENTITY is indexed under UNKNOWN (see above) */
          asearch = (aout == IDENTITY2) ? UNKNOWN1 : aout;
          if (aout < 0) continue;
          iptr = outarray+(asearch*(max2sigma+2));
          currtail = (index+asearch)->tail + 1;
          for ( ; iptr != currtail && iptr->mainloop == mainloop ; iptr++) {

              ain = machine_a->in;
              aout = machine_a->out;
              bin = iptr->symin;
              bout = iptr->symout;

              if (aout == IDENTITY2 && bin == UNKNOWN1) {
                  ain = aout = UNKNOWN1;
              }
              else if (aout == UNKNOWN1 && bin == IDENTITY2) {
                  bin = bout = UNKNOWN1;
              }

              if (!g_compose_tristate) {
                  if (bin == aout && bin != -1 && bin != EPSILON0) {
                      /* mode -> 0 */
                      if ((target_number = triplet_hash_find(th, machine_a->target, iptr->target, 0)) == -1) {
                          STACK_3_PUSH(0, iptr->target, machine_a->target)int_stack_push(0); int_stack_push(iptr->target); int_stack_push
(machine_a->target);;
                          target_number = triplet_hash_insert(th, machine_a->target, iptr->target, 0);
                      }

                      fsm_state_add_arc(current_state, ain, bout, target_number, current_final, current_start);
                  }
              }

              else if (g_compose_tristate) {
                  if (bin == aout && bin != -1 && ((bin != EPSILON0 || mode == 0))) {
                      /* mode -> 0 */
                      if ((target_number = triplet_hash_find(th, machine_a->target, iptr->target, 0)) == -1) {
                          STACK_3_PUSH(0, iptr->target, machine_a->target)int_stack_push(0); int_stack_push(iptr->target); int_stack_push
(machine_a->target);;
                          target_number = triplet_hash_insert(th, machine_a->target, iptr->target, 0);
                      }

                      fsm_state_add_arc(current_state, ain, bout, target_number, current_final, current_start);
                  }
              }

          }
      }

      /* Treat epsilon outputs on machine a (may include flags) */
      for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a ; machine_a++) {
          aout = machine_a->out;
          if (aout != EPSILON0 && g_flag_is_epsilon == 0)
              continue;
          ain = machine_a->in;

          if (g_flag_is_epsilon && aout != -1 && mode == 0 && *(is_flag+aout)) {
              if ((target_number = triplet_hash_find(th, machine_a->target, b, 0)) == -1) {
                  STACK_3_PUSH(0, b, machine_a->target)int_stack_push(0); int_stack_push(b); int_stack_push(machine_a
->target);;
    target_number = triplet_hash_insert(th, machine_a->target, b, 0);
              }
              fsm_state_add_arc(current_state, ain, aout, target_number, current_final, current_start);
          }

          if (!g_compose_tristate) {
              /* Check A:0 arcs on upper side */
              if (aout == EPSILON0 && mode == 0) {
                  /* mode -> 0 */
                  if ((target_number = triplet_hash_find(th, machine_a->target, b, 0)) == -1) {
                      STACK_3_PUSH(0, b, machine_a->target)int_stack_push(0); int_stack_push(b); int_stack_push(machine_a
->target);;
                      target_number = triplet_hash_insert(th, machine_a->target, b, 0);
                  }

                  fsm_state_add_arc(current_state, ain, EPSILON0, target_number, current_final, current_start);
              }
          }

          else if (g_compose_tristate) {
              if (aout == EPSILON0 && (mode != 2)) {
                  /* mode -> 1 */
                  if ((target_number = triplet_hash_find(th, machine_a->target, b, 1)) == -1) {
                      STACK_3_PUSH(1, b, machine_a->target)int_stack_push(1); int_stack_push(b); int_stack_push(machine_a
->target);;
                      target_number = triplet_hash_insert(th, machine_a->target, b, 1);
                  }

                  fsm_state_add_arc(current_state, ain, EPSILON0, target_number, current_final, current_start);

              }
          }

      }
      /* Treat epsilon inputs on machine b (may include flags) */
      for (machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {
          bin = machine_b->in;
          if (bin != EPSILON0 && g_flag_is_epsilon == 0)
              continue;

          bout = machine_b->out;

          if (g_flag_is_epsilon && bin != -1 && *(is_flag+bin)) {
              if ((target_number = triplet_hash_find(th, a, machine_b->target, 1)) == -1) {
                  STACK_3_PUSH(1, machine_b->target,a)int_stack_push(1); int_stack_push(machine_b->target); int_stack_push
(a);;
                  target_number = triplet_hash_insert(th, a, machine_b->target, 1);
              }
              fsm_state_add_arc(current_state, bin, bout, target_number, current_final, current_start);
          }

          if (!g_compose_tristate) {
              /* Check 0:A arcs on lower side */
              if (bin == EPSILON0) {
                  /* mode -> 1 */
                  if ((target_number = triplet_hash_find(th, a, machine_b->target, 1)) == -1) {
                      STACK_3_PUSH(1, machine_b->target,a)int_stack_push(1); int_stack_push(machine_b->target); int_stack_push
(a);;
                      target_number = triplet_hash_insert(th, a, machine_b->target, 1);
                  }

                  fsm_state_add_arc(current_state, EPSILON0, bout, target_number, current_final, current_start);
              }
          }

          else if (g_compose_tristate) {
              /* Check 0:A arcs on lower side */
              if (bin == EPSILON0 && mode != 1) {
                  /* mode -> 1 */
                  if ((target_number = triplet_hash_find(th, a, machine_b->target, 2)) == -1) {
                      STACK_3_PUSH(2, machine_b->target, a)int_stack_push(2); int_stack_push(machine_b->target); int_stack_push
(a);;
                      target_number = triplet_hash_insert(th, a, machine_b->target, 2);
                  }

                  fsm_state_add_arc(current_state, EPSILON0, bout, target_number, current_final, current_start);
              }
          }
      }
      fsm_state_end_state();
  }

  free(net1->states);
  fsm_destroy(net2);
  fsm_state_close(net1);
  free(point_a);
  free(point_b);
  free(index);
  free(outarray);

  if (g_flag_is_epsilon)
      free(is_flag);
  triplet_hash_free(th);
  net1 = fsm_topsort(fsm_coaccessible(net1));
  return(fsm_coaccessible(net1));
841}

843struct mergesigma *add_to_mergesigma(struct mergesigma *msigma, struct sigma *sigma, short presence) {
int number = 0;

if (msigma->number == -1) {
  number = 2;
} else {
  msigma->next = malloc(sizeof(struct mergesigma));
  number = msigma->number;
  msigma = msigma->next;
  msigma->next = NULL((void*)0);
}

if (sigma->number < 3) {
  msigma->number = sigma->number;
} else {
  if (number < 3)
    number = 2;
  msigma->number = number+1;
}
msigma->symbol = sigma->symbol;
msigma->presence = presence;
return(msigma);
865}

867struct sigma *copy_mergesigma(struct mergesigma *mergesigma) {
  struct sigma *sigma, *new_sigma;

  sigma = new_sigma = NULL((void*)0);
  while(mergesigma != NULL((void*)0)) {
if (sigma == NULL((void*)0)) {
   sigma = malloc(sizeof(struct sigma));
   new_sigma = sigma;
} else {
   sigma->next = malloc(sizeof(struct sigma));
   sigma = sigma->next;
}
sigma->next = NULL((void*)0);
sigma->number = mergesigma->number;

sigma->symbol = NULL((void*)0);
if (mergesigma->symbol != NULL((void*)0))
   sigma->symbol = strdup(mergesigma->symbol);
mergesigma = mergesigma->next;
  }
  return(new_sigma);
888}

890void fsm_merge_sigma(struct fsm *net1, struct fsm *net2) {

struct sigma *sigma_1, *sigma_2, *new_sigma_1 = NULL((void*)0), *new_sigma_2 = NULL((void*)0);
struct mergesigma *mergesigma, *mergesigma2, *start_mergesigma;
struct fsm_state *fsm_state, *new_1_state, *new_2_state;
int i, j, end_1 = 0, end_2 = 0, sigmasizes, *mapping_1, *mapping_2, equal = 1, unknown_1 = 0, unknown_2 = 0, net_unk = 0, net_adds = 0, net_lines;

if (!fsm_options.skip_word_boundary_marker) {
  i = sigma_find(".#.", net1->sigma);
  j = sigma_find(".#.", net2->sigma);
  if (i != -1 && j == -1) {
    sigma_add(".#.", net2->sigma);
    sigma_sort(net2);
  }
  if (j != -1 && i == -1) {
    sigma_add(".#.", net1->sigma);
    sigma_sort(net1);
  }
}

sigma_1 = net1->sigma;
sigma_2 = net2->sigma;

sigmasizes = sigma_max(sigma_1) + sigma_max(sigma_2) + 3;

mapping_1 = malloc(sizeof(int)*sigmasizes);
mapping_2 = malloc(sizeof(int)*sigmasizes);

/* Fill mergesigma */

mergesigma = malloc(sizeof(struct mergesigma));
mergesigma->number = -1;
mergesigma->symbol = NULL((void*)0);
mergesigma->next = NULL((void*)0);
start_mergesigma = mergesigma;

/* Loop over sigma 1, sigma 2 */
for (;;) {
  if (sigma_1 == NULL((void*)0))
    end_1 = 1;
  if (sigma_2 == NULL((void*)0))
    end_2 = 1;
  if (end_1 && end_2)
    break;
  if (end_2) {
    /* Treating only 1 now */
    mergesigma = add_to_mergesigma(mergesigma, sigma_1, 1);
    *(mapping_1+(sigma_1->number)) = mergesigma->number;
    sigma_1 = sigma_1->next;
    equal = 0;
    continue;
  }
  else if (end_1) {
    /* Treating only 2 now */
    mergesigma = add_to_mergesigma(mergesigma, sigma_2, 2);
    *(mapping_2+(sigma_2->number)) = mergesigma->number;
    sigma_2 = sigma_2->next;
    equal = 0;
    continue;
  }

  else {

    /* Both alive */

    /* 1 or 2 contains special characters */
    if ((sigma_1->number <= IDENTITY2) || (sigma_2->number <= IDENTITY2)) {

/* Treating zeros or unknowns */

if ((sigma_1->number == UNKNOWN1) || (sigma_1->number == IDENTITY2))
 unknown_1 = 1;
if ((sigma_2->number == UNKNOWN1) || (sigma_2->number == IDENTITY2))
 unknown_2 = 1;

if (sigma_1->number == sigma_2->number) {
 mergesigma = add_to_mergesigma(mergesigma, sigma_1, 3);
 sigma_1 = sigma_1->next;
 sigma_2 = sigma_2->next;
}
else if (sigma_1->number < sigma_2->number) {
 mergesigma = add_to_mergesigma(mergesigma, sigma_1, 1);
 sigma_1 = sigma_1->next;
 equal = 0;
}
else {
 mergesigma = add_to_mergesigma(mergesigma, sigma_2, 2);
 sigma_2 = sigma_2->next;
 equal = 0;
}
continue;
    }
    /* Both contain non-special chars */
    if (strcmp(sigma_1->symbol, sigma_2->symbol) == 0) {
      mergesigma = add_to_mergesigma(mergesigma, sigma_1, 3);
/* Add symbol numbers to mapping */
*(mapping_1+(sigma_1->number)) = mergesigma->number;
*(mapping_2+(sigma_2->number)) = mergesigma->number;

sigma_1 = sigma_1->next;
sigma_2 = sigma_2->next;
    }
    else if (strcmp(sigma_1->symbol, sigma_2->symbol) < 0) {
mergesigma = add_to_mergesigma(mergesigma, sigma_1, 1);
*(mapping_1+(sigma_1->number)) = mergesigma->number;
sigma_1 = sigma_1->next;
equal = 0;
    }
    else {
mergesigma = add_to_mergesigma(mergesigma, sigma_2, 2);
*(mapping_2+(sigma_2->number)) = mergesigma->number;
sigma_2 = sigma_2->next;
equal = 0;
    }
    continue;
  }
}

/* Go over both net1 and net2 and replace arc numbers with new mappings */

fsm_state = net1->states;
for (i=0; (fsm_state+i)->state_no != -1; i++) {
  if ((fsm_state+i)->in > 2)
    (fsm_state+i)->in = *(mapping_1+(fsm_state+i)->in);
  if ((fsm_state+i)->out > 2)
    (fsm_state+i)->out = *(mapping_1+(fsm_state+i)->out);
}
fsm_state = net2->states;
for (i=0; (fsm_state+i)->state_no != -1; i++) {
  if ((fsm_state+i)->in > 2)
    (fsm_state+i)->in = *(mapping_2+(fsm_state+i)->in);
  if ((fsm_state+i)->out > 2)
    (fsm_state+i)->out = *(mapping_2+(fsm_state+i)->out);
}

/* Copy mergesigma to net1, net2 */

new_sigma_1 = copy_mergesigma(start_mergesigma);
new_sigma_2 = copy_mergesigma(start_mergesigma);

fsm_sigma_destroy(net1->sigma);
fsm_sigma_destroy(net2->sigma);

net1->sigma = new_sigma_1;
net2->sigma = new_sigma_2;

/* Expand on ?, ?:x, y:? */

if (unknown_1 && !equal) {
  /* Expand net 1 */
  fsm_state = net1->states;
  net_lines = find_arccount(net1->states);
  for(mergesigma = start_mergesigma; mergesigma != NULL((void*)0); mergesigma=mergesigma->next) {
    if(mergesigma->presence == 2) {
net_unk++;
    }
  }
  for(net_adds = 0, i=0; (fsm_state+i)->state_no != -1; i++) {
    if ((fsm_state+i)->in == IDENTITY2)
net_adds += net_unk;
    if (((fsm_state+i)->in == UNKNOWN1) && ((fsm_state+i)->out != UNKNOWN1))
net_adds += net_unk;
    if (((fsm_state+i)->out == UNKNOWN1) && ((fsm_state+i)->in != UNKNOWN1))
net_adds += net_unk;
    if (((fsm_state+i)->in == UNKNOWN1) && ((fsm_state+i)->out == UNKNOWN1))
net_adds += net_unk*net_unk - net_unk + 2*net_unk;
  }

  new_1_state = malloc(sizeof(struct fsm_state)*(net_adds+net_lines+1));
  for(i=0,j=0; (fsm_state+i)->state_no != -1; i++) {

    if ((fsm_state+i)->in == IDENTITY2) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma != NULL((void*)0); mergesigma=mergesigma->next) {
 if ((mergesigma->presence == 2) && (mergesigma->number > IDENTITY2)) {
   add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, mergesigma->number, mergesigma->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    if ((fsm_state+i)->in == UNKNOWN1 && (fsm_state+i)->out != UNKNOWN1) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
 if ((mergesigma->presence == 2) && (mergesigma->number > IDENTITY2)) {
   add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, mergesigma->number, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    if (((fsm_state+i)->in != UNKNOWN1) && ((fsm_state+i)->out == UNKNOWN1)) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma != NULL((void*)0); mergesigma = mergesigma->next) {
 if ((mergesigma->presence == 2) && (mergesigma->number > IDENTITY2)) {
   add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, mergesigma->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    /* Replace ?:? with ?:[all unknowns] [all unknowns]:? and [all unknowns]:[all unknowns] where a != b */
    if ((fsm_state+i)->in == UNKNOWN1 && (fsm_state+i)->out == UNKNOWN1) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma2=start_mergesigma; mergesigma2 != NULL((void*)0) ; mergesigma2 = mergesigma2->next) {
 for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
   if (((mergesigma->presence == 2 && mergesigma2->presence == 2 && mergesigma->number > IDENTITY2 && mergesigma2->number > IDENTITY2) || (mergesigma->number == UNKNOWN1 && mergesigma2->number > IDENTITY2 && mergesigma2->presence == 2) || (mergesigma2->number == UNKNOWN1 && mergesigma->number > IDENTITY2 && mergesigma->presence == 2)) && mergesigma->number != mergesigma2->number) {
     add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, mergesigma->number, mergesigma2->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
     j++;
   }
 }
}
    }

    /* Simply copy arcs that are not IDENTITY or UNKNOWN */
    if (((fsm_state+i)->in > IDENTITY2 || (fsm_state+i)->in == EPSILON0) && ((fsm_state+i)->out > IDENTITY2 || (fsm_state+i)->out == EPSILON0)) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
    }

    if ((fsm_state+i)->in == -1) {
add_fsm_arc(new_1_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
    }
  }

  add_fsm_arc(new_1_state, j, -1, -1, -1, -1, -1, -1);
  free(net1->states);
  net1->states = new_1_state;
}

if (unknown_2 && !equal) {
  /* Expand net 2 */
  fsm_state = net2->states;
  net_lines = find_arccount(net2->states);
  for(net_unk = 0, mergesigma = start_mergesigma; mergesigma != NULL((void*)0); mergesigma=mergesigma->next) {
    if(mergesigma->presence == 1) {
net_unk++;
    }
  }

  for(net_adds = 0, i=0; (fsm_state+i)->state_no != -1; i++) {
    if ((fsm_state+i)->in == IDENTITY2)
net_adds += net_unk;
    if (((fsm_state+i)->in == UNKNOWN1) && ((fsm_state+i)->out != UNKNOWN1))
net_adds += net_unk;
    if (((fsm_state+i)->out == UNKNOWN1) && ((fsm_state+i)->in != UNKNOWN1))
net_adds += net_unk;
    if (((fsm_state+i)->in == UNKNOWN1) && ((fsm_state+i)->out == UNKNOWN1))
net_adds += net_unk*net_unk - net_unk + 2*net_unk;
  }

  /* We need net_add new lines in fsm_state */
  new_2_state = malloc(sizeof(struct fsm_state)*(net_adds+net_lines+1));
  for(i=0,j=0; (fsm_state+i)->state_no != -1; i++) {

    if ((fsm_state+i)->in == IDENTITY2) {
add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
 if ((mergesigma->presence == 1) && (mergesigma->number > IDENTITY2)) {
   add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, mergesigma->number, mergesigma->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    if ((fsm_state+i)->in == UNKNOWN1 && (fsm_state+i)->out != UNKNOWN1) {
add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
 if (mergesigma->presence == 1 && mergesigma->number > IDENTITY2) {
   add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, mergesigma->number, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    if ((fsm_state+i)->in != UNKNOWN1 && (fsm_state+i)->out == UNKNOWN1) {
add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
 if ((mergesigma->presence == 1) && (mergesigma->number > IDENTITY2)) {
   add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, mergesigma->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
   j++;
 }
}
    }

    if ((fsm_state+i)->in == UNKNOWN1 && (fsm_state+i)->out == UNKNOWN1) {
add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
for (mergesigma2=start_mergesigma; mergesigma2 != NULL((void*)0) ; mergesigma2 = mergesigma2->next) {
 for (mergesigma=start_mergesigma; mergesigma!=NULL((void*)0); mergesigma=mergesigma->next) {
   if (((mergesigma->presence == 1 && mergesigma2->presence == 1 && mergesigma->number > IDENTITY2 && mergesigma2->number > IDENTITY2) || (mergesigma->number == UNKNOWN1 && mergesigma2->number > IDENTITY2 && mergesigma2->presence == 1) || (mergesigma2->number == UNKNOWN1 && mergesigma->number > IDENTITY2 && mergesigma->presence == 1)) && mergesigma->number != mergesigma2->number) {
     add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, mergesigma->number, mergesigma2->number, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
     j++;
   }
 }
}
    }

    /* Simply copy arcs that are not IDENTITY or UNKNOWN */
    if (((fsm_state+i)->in > IDENTITY2 || (fsm_state+i)->in == EPSILON0) && ((fsm_state+i)->out > IDENTITY2 || (fsm_state+i)->out == EPSILON0)) {

add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
    }

    if ((fsm_state+i)->in == -1) {
add_fsm_arc(new_2_state, j, (fsm_state+i)->state_no, (fsm_state+i)->in, (fsm_state+i)->out, (fsm_state+i)->target, (fsm_state+i)->final_state, (fsm_state+i)->start_state);
j++;
    }
  }

  add_fsm_arc(new_2_state, j, -1, -1, -1, -1, -1, -1);
  free(net2->states);
  net2->states = new_2_state;
}
free(mapping_1);
free(mapping_2);

/* Free structure */
for (mergesigma2 = NULL((void*)0); start_mergesigma != NULL((void*)0); ) {
    mergesigma2 = start_mergesigma;
    start_mergesigma = start_mergesigma->next;
    free(mergesigma2);
}
1222}


1225int add_fsm_arc(struct fsm_state *fsm, int offset, int state_no, int in, int out, int target, int final_state, int start_state) {

(fsm+offset)->state_no = state_no;
(fsm+offset)->in = in;
(fsm+offset)->out= out;
(fsm+offset)->target = target;
(fsm+offset)->final_state = final_state;
(fsm+offset)->start_state = start_state;
offset++;
return(offset);
1235}


1238void fsm_count(struct fsm *net) {
struct fsm_state *fsm;
int i, linecount, arccount, oldstate, finalcount, maxstate;
linecount = arccount = finalcount = maxstate = 0;

oldstate = -1;

fsm = net->states;
for (i=0; (fsm+i)->state_no != -1; i++) {
  if ((fsm+i)->state_no > maxstate)
    maxstate = (fsm+i)->state_no;

  linecount++;
  if ((fsm+i)->target != -1) {
      arccount++;
//        if (((fsm+i)->in != (fsm+i)->out) || ((fsm+i)->in == UNKNOWN) || ((fsm+i)->out == UNKNOWN))
      //    arity = 2;
  }
  if ((fsm+i)->state_no != oldstate) {
      if ((fsm+i)->final_state) {
          finalcount++;
      }
      oldstate = (fsm+i)->state_no;
  }
}

linecount++;
net->statecount = maxstate+1;
net->linecount = linecount;
net->arccount = arccount;
net->finalcount = finalcount;
1269}

1271static void fsm_add_to_states(struct fsm *net, int add) {
struct fsm_state *fsm;
int i;

fsm=net->states;
for(i=0; (fsm+i)->state_no != -1; i++) {
  (fsm+i)->state_no = (fsm+i)->state_no + add;
  if ((fsm+i)->target != -1)
    (fsm+i)->target = (fsm+i)->target + add;
}
1281}

1283struct fsm *fsm_concat_m_n(struct fsm *net1, int m, int n) {
struct fsm *acc;
  int i;
  acc = fsm_empty_string();
  for (i = 1; i <= n ;i++) {
      if (i > m)
          acc = fsm_concat(acc, fsm_optionality(fsm_copy(net1)));
      else
          acc = fsm_concat(acc, fsm_copy(net1));
  }
  fsm_destroy(net1);
  return(acc);
1295}

1297struct fsm *fsm_concat_n(struct fsm *net1, int n) {
  return(fsm_concat_m_n(net1,n,n));
1299}

1301struct fsm *fsm_concat(struct fsm *net1, struct fsm *net2) {
struct fsm_state *fsm1, *fsm2, *new_fsm;
int i,j,current_final;

fsm_merge_sigma(net1, net2);

fsm1 = net1->states;
fsm2 = net2->states;
fsm_count(net1);
fsm_count(net2);
/* The concatenation of a language with no final state should yield the empty language */
if ((net1->finalcount == 0) || (net2->finalcount == 0)) {
    fsm_destroy(net1);
    fsm_destroy(net2);
    net1 = fsm_empty_set();
    return(net1);
}

/* Add |fsm1| states to the state numbers of fsm2 */
fsm_add_to_states(net2, net1->statecount);

new_fsm = malloc(((sizeof(struct fsm_state))*(net1->linecount + net2->linecount + net1->finalcount + 2 )));
current_final = -1;
/* Copy fsm1, fsm2 after each other, adding appropriate epsilon arcs */
for(i=0,j=0; (fsm1+i)->state_no != -1; i++) {
  if (((fsm1+i)->final_state == 1) && ((fsm1+i)->state_no != current_final)) {
    add_fsm_arc(new_fsm, j, (fsm1+i)->state_no, EPSILON0, EPSILON0, net1->statecount, 0, (fsm1+i)->start_state);
    current_final = (fsm1+i)->state_no;
    j++;
  }
  if (!(((fsm1+i)->target == -1) && ((fsm1+i)->final_state == 1))) {
    add_fsm_arc(new_fsm, j, (fsm1+i)->state_no, (fsm1+i)->in, (fsm1+i)->out, (fsm1+i)->target, 0, (fsm1+i)->start_state);
    j++;
  }
}

for(i=0; (fsm2+i)->state_no != -1; i++, j++) {
  add_fsm_arc(new_fsm, j, (fsm2+i)->state_no, (fsm2+i)->in, (fsm2+i)->out, (fsm2+i)->target, (fsm2+i)->final_state, 0);
}
add_fsm_arc(new_fsm, j, -1, -1, -1, -1, -1, -1);
free(net1->states);
fsm_destroy(net2);
net1->states = new_fsm;
if (sigma_find_number(EPSILON0, net1->sigma) == -1) {
  sigma_add_special(EPSILON0, net1->sigma);
}
fsm_count(net1);
net1->is_epsilon_free = NO0;
net1->is_deterministic = NO0;
net1->is_minimized = NO0;
net1->is_pruned = NO0;
return(fsm_minimize(net1));
1353}

1355struct fsm *fsm_union(struct fsm *net1, struct fsm *net2) {
  struct fsm_state *new_fsm, *fsm1, *fsm2;
  int i, j, net1_offset, net2_offset, new_target, arccount;

  fsm_merge_sigma(net1, net2);

  fsm_count(net1);
  fsm_count(net2);

  fsm1 = net1->states;
  fsm2 = net2->states;

  net1_offset = 1;
  net2_offset = net1->statecount + 1;
  new_fsm = malloc((net1->linecount + net2->linecount + 2) * sizeof(struct fsm_state));

  j = 0;

  add_fsm_arc(new_fsm, j++, 0, EPSILON0, EPSILON0, net1_offset, 0 , 1);
  add_fsm_arc(new_fsm, j++, 0, EPSILON0, EPSILON0, net2_offset, 0 , 1);
  arccount = 2;
  for (i=0 ; (fsm1+i)->state_no != -1; i++) {
      new_target = (fsm1+i)->target == -1 ? -1 : (fsm1+i)->target + net1_offset;
      add_fsm_arc(new_fsm, j++, (fsm1+i)->state_no + net1_offset, (fsm1+i)->in, (fsm1+i)->out, new_target, (fsm1+i)->final_state, 0);
      if (new_target != -1) arccount++;
  }
  for (i=0 ; (fsm2+i)->state_no != -1; i++) {
      new_target = (fsm2+i)->target == -1 ? -1 : (fsm2+i)->target + net2_offset;
      add_fsm_arc(new_fsm, j++, (fsm2+i)->state_no + net2_offset, (fsm2+i)->in, (fsm2+i)->out, new_target, (fsm2+i)->final_state, 0);
      if (new_target != -1) arccount++;
  }
  add_fsm_arc(new_fsm, j++, -1, -1, -1, -1, -1, -1);
  free(net1->states);
  net1->states = new_fsm;
  net1->statecount = net1->statecount + net2->statecount + 1;
  net1->linecount = j;
  net1->arccount = arccount;
  net1->finalcount = net1->finalcount + net2->finalcount;
  fsm_destroy(net2);
  fsm_update_flags(net1,NO0,NO0,NO0,NO0,UNK2,NO0);
  if (sigma_find_number(EPSILON0, net1->sigma) == -1) {
      sigma_add_special(EPSILON0, net1->sigma);
  }
  return(net1);
1399}

1401struct fsm *fsm_completes(struct fsm *net, int operation) {
struct fsm_state *fsm, *new_fsm;
int i, j, offset, statecount, sigsize, *state_table, sink_state, target, last_sigma = 0, arccount = 0, incomplete;
short *starts, *finals, *sinks;

/* TODO: this currently relies on that the sigma is gap-free in its numbering  */
/* which can't always be counted on, especially when reading external machines */

/* TODO: check arity */

if (net->is_minimized != YES1)
    net = fsm_minimize(net);

incomplete = 0;
fsm = net->states;
if (sigma_find_number(UNKNOWN1, net->sigma) != -1) {
    sigma_remove("@_UNKNOWN_SYMBOL_@",net->sigma);
}
if (sigma_find_number(IDENTITY2, net->sigma) == -1) {
  sigma_add_special(IDENTITY2, net->sigma);
  incomplete = 1;
}

sigsize = sigma_size(net->sigma);
last_sigma = sigma_max(net->sigma);

if (sigma_find_number(EPSILON0, net->sigma) != -1)
    sigsize--;

fsm_count(net);
statecount = net->statecount;
starts = malloc(sizeof(short)*(statecount+1)); /* +1 for sink state */
finals = malloc(sizeof(short)*(statecount+1));
sinks = malloc(sizeof(short)*(statecount+1));

/* Init starts, finals, sinks arrays */

for (i=0; i < statecount; i++) {
  *(sinks+i) = 1;
  *(finals+i) = 0;
  *(starts+i) = 0;
}
for (i=0; (fsm+i)->state_no != -1; i++) {
  if (operation == COMPLEMENT0) {
    if ((fsm+i)->final_state == 1) {
(fsm+i)->final_state = 0;
    } else if ((fsm+i)->final_state == 0) {
(fsm+i)->final_state = 1;
    }
  }
  if ((fsm+i)->target != -1)
    arccount++;
  starts[(fsm+i)->state_no] = (fsm+i)->start_state;
  finals[(fsm+i)->state_no] = (fsm+i)->final_state;
  if ((fsm+i)->final_state && operation != COMPLEMENT0)
    *(sinks+((fsm+i)->state_no)) = 0;
  if ((fsm+i)->final_state == 0 && (operation == COMPLEMENT0))
    *(sinks+((fsm+i)->state_no)) = 0;
  if (((fsm+i)->target != -1) && ((fsm+i)->state_no != (fsm+i)->target))
    *(sinks+((fsm+i)->state_no)) = 0;
}

net->is_loop_free = NO0;
net->pathcount = PATHCOUNT_CYCLIC-1;

if (incomplete == 0 && (arccount == (sigsize)*statecount)) {
  /*    printf("Already complete!\n"); */

1469/*     if (operation == COMPLEMENT) { */
1470/*       for (i=0; (fsm+i)->state_no != -1; i++) { */
1471/* 	if ((fsm+i)->final_state) { */
1472/* 	  (fsm+i)->final_state = 0; */
1473/* 	} else { */
1474/* 	  (fsm+i)->final_state = 1; */
1475/* 	} */
1476/*       } */
1477/*     } */
  free(starts);
  free(finals);
  free(sinks);
  net->is_completed = YES1;
  net->is_minimized = YES1;
  net->is_pruned = NO0;
  net->is_deterministic = YES1;
  return(net);
}

/* Find an existing sink state, or invent a new one */

for (i=0, sink_state = -1; i<statecount; i++) {
  if (sinks[i] == 1) {
    sink_state = i;
    break;
  }
}

if (sink_state == -1) {
  sink_state = statecount;
  *(starts+sink_state) = 0;
  if (operation == COMPLEMENT0) {
    *(finals+sink_state) = 1;
  } else {
    *(finals+sink_state) = 0;
  }
  statecount++;
}


/* We can build a state table without memory problems since the size */
/* of the completed machine will be |Sigma| * |States| in all cases */

sigsize += 2;

state_table = malloc(sizeof(int)*sigsize*statecount);

/* Init state table */
/* i = state #, j = sigma # */
for (i=0; i<statecount; i++) {
  for (j=0; j<sigsize; j++) {
    *(state_table+(i*sigsize+j)) = -1;
  }
}

for (i=0; (fsm+i)->state_no != -1; i++) {
  if ((fsm+i)->target != -1) {
    *(state_table+(((fsm+i)->state_no)*sigsize+((fsm+i)->in))) = (fsm+i)->target;
  }
}
/* Add looping arcs from and to sink state */
for (j=2; j<=last_sigma; j++)
    *(state_table+(sink_state*sigsize+j)) = sink_state;
/* Add missing arcs to sink state from all states */
for (i=0; i<statecount; i++) {
  for (j=2; j<=last_sigma; j++) {
    if (*(state_table+(i*sigsize+j)) == -1)
*(state_table+(i*sigsize+j)) = sink_state;
  }
}

new_fsm = malloc(sizeof(struct fsm_state)*(sigsize*statecount+1));

1542/* Complement requires toggling final, nonfinal states */
1543/*   if (operation == COMPLEMENT) */
1544/*     for (i=0; i < statecount; i++) */
1545/*       *(finals+i) = *(finals+i) == 0 ? 1 : 0; */

for (i=0, offset = 0; i<statecount; i++) {
  for (j=2; j<=last_sigma; j++) {
    target = *(state_table+(i*sigsize+j)) == -1 ? sink_state : *(state_table+(i*sigsize+j));
    add_fsm_arc(new_fsm, offset, i, j, j, target, finals[i], starts[i]);
    offset++;
  }
}
add_fsm_arc(new_fsm, offset, -1, -1, -1, -1, -1, -1);
offset++;
free(net->states);
net->states = new_fsm;
free(starts);
free(finals);
free(sinks);
free(state_table);
net->is_minimized = NO0;
net->is_pruned = NO0;
net->is_completed = YES1;
net->statecount = statecount;
return(net);
1567}

1569struct fsm *fsm_complete(struct fsm *net) {
return(fsm_completes(net, COMPLETE1));
1571}

1573struct fsm *fsm_complement(struct fsm *net) {
return(fsm_completes(net, COMPLEMENT0));
1575}

1577struct fsm *fsm_kleene_closure(struct fsm *net, int operation) {
  struct fsm_state *fsm, *new_fsm;
  int i, j, laststate, curr_state, curr_target, arccount;

  if (operation == OPTIONALITY2) {
      return(fsm_union(net,fsm_empty_string()));
  }

  net = fsm_minimize(net);
  fsm_count(net);

  fsm = net->states;

  new_fsm = malloc( (net->linecount + net->finalcount + 1) * sizeof(struct fsm_state));

  j = 0;
  if (operation == KLEENE_STAR0)
      add_fsm_arc(new_fsm, j++, 0, EPSILON0, EPSILON0, 1, 1, 1);
  if (operation == KLEENE_PLUS1)
      add_fsm_arc(new_fsm, j++, 0, EPSILON0, EPSILON0, 1, 0, 1);
  laststate = 0;
  arccount = 1;
  for (i = 0 ; (fsm+i)->state_no != -1; i++, laststate = curr_state) {
      curr_state = (fsm+i)->state_no + 1;
      curr_target = (fsm+i)->target == -1 ? -1 : (fsm+i)->target + 1;
      if (curr_target == -1 && (fsm+i)->final_state == 1) {
          add_fsm_arc(new_fsm, j++, curr_state, EPSILON0, EPSILON0, 0, 1, 0);
          arccount++;
          continue;
      }
      if (curr_state != laststate && (fsm+i)->final_state == 1) {
          arccount++;
          add_fsm_arc(new_fsm, j++, curr_state, EPSILON0, EPSILON0, 0, 1, 0);
      }
      add_fsm_arc(new_fsm, j++, curr_state, (fsm+i)->in, (fsm+i)->out, curr_target, (fsm+i)->final_state, 0);
      if (curr_target != -1) arccount++;
  }
  add_fsm_arc(new_fsm, j++, -1,-1,-1,-1,-1,-1);
  net->statecount = net->statecount+1;
  net->linecount = j;
  net->finalcount = operation == KLEENE_STAR0 ? net->finalcount+1 : net->finalcount;
  net->arccount = arccount;
  net->pathcount = PATHCOUNT_UNKNOWN-3;
  free(net->states);
  net->states = new_fsm;
  if (sigma_find_number(EPSILON0, net->sigma) == -1)
      sigma_add_special(EPSILON0, net->sigma);
  fsm_update_flags(net,NO0,NO0,NO0,NO0,UNK2,NO0);
  return(net);
1626}

1628char *fsm_network_to_char(struct fsm *net) {
  struct sigma *sigma, *sigprev;
  sigma = net->sigma;
  if (sigma->number == -1) {
      return NULL((void*)0);
  }
  for (; sigma != NULL((void*)0) && sigma->number != -1 ; sigma = sigma->next) {
sigprev = sigma;
  }
  return(strdup(sigprev->symbol));
1638}

1640struct fsm *fsm_substitute_label(struct fsm *net, char *original, struct fsm *substitute) {

  struct fsm *outnet, *subnet2;
  struct fsm_read_handle *inh, *subh, *subh2;
  struct fsm_construct_handle *outh;
  char *subin, *subout;
  int i, repsym, source, target, in, out, addstate1, addstate2;

  fsm_merge_sigma(net, substitute);
  addstate1 = net->statecount;
  addstate2 = substitute->statecount;

  inh = fsm_read_init(net);
  subh = fsm_read_init(substitute);
  repsym = fsm_get_symbol_number(inh, original);
  if (repsym == -1) {
fsm_read_done(inh);
return(net);
  }
  outh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(outh, net->sigma);
  while (fsm_get_next_arc(inh)) {
source = fsm_get_arc_source(inh);
target = fsm_get_arc_target(inh);
in = fsm_get_arc_num_in(inh);
out = fsm_get_arc_num_out(inh);

/* Double-sided arc, splice in substitute network */
if (in == repsym && out == repsym) {
   fsm_read_reset(subh);
   fsm_construct_add_arc_nums(outh, source, addstate1, EPSILON0, EPSILON0);
   while (fsm_get_next_arc(subh)) {
source = fsm_get_arc_source(subh);
target = fsm_get_arc_target(subh);
subin = fsm_get_arc_in(subh);
subout = fsm_get_arc_out(subh);
fsm_construct_add_arc(outh, source+addstate1, target+addstate1, subin, subout);
   }
   while ((i = fsm_get_next_final(subh)) != -1) {
target = fsm_get_arc_target(inh);
fsm_construct_add_arc_nums(outh, addstate1+i, target, EPSILON0, EPSILON0);
   }
   addstate1 = addstate1 + addstate2;
   /* One-sided replace, splice in repsym .x. sub or sub .x. repsym */
} else if (in == repsym || out == repsym) {
   if (in == repsym) {
subnet2 = fsm_minimize(fsm_cross_product(fsm_copy(substitute), fsm_symbol(fsm_get_arc_out(inh))));
   } else {
subnet2 = fsm_minimize(fsm_cross_product(fsm_symbol(fsm_get_arc_in(inh)),fsm_copy(substitute)));
   }
   fsm_construct_add_arc_nums(outh, source, addstate1, EPSILON0, EPSILON0);
   subh2 = fsm_read_init(subnet2);
   while (fsm_get_next_arc(subh2)) {
source = fsm_get_arc_source(subh2);
target = fsm_get_arc_target(subh2);
subin = fsm_get_arc_in(subh2);
subout = fsm_get_arc_out(subh2);
fsm_construct_add_arc(outh, source+addstate1, target+addstate1, subin, subout);
   }
   while ((i = fsm_get_next_final(subh2)) != -1) {
target = fsm_get_arc_target(inh);
fsm_construct_add_arc_nums(outh, addstate1+i, target, EPSILON0, EPSILON0);
   }
   fsm_read_done(subh2);
   addstate1 = addstate1 + subnet2->statecount;
   fsm_destroy(subnet2);
} else {
   /* Default, just copy arc */
   fsm_construct_add_arc_nums(outh, source, target, in, out);
}
  }

  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(outh, i);
  }
  while ((i = fsm_get_next_initial(inh)) != -1) {
fsm_construct_set_initial(outh, i);
  }
  fsm_read_done(inh);
  fsm_read_done(subh);
  outnet = fsm_construct_done(outh);
  return(outnet);
1722}

1724struct fsm *fsm_substitute_symbol(struct fsm *net, char *original, char *substitute) {
  struct fsm_state *fsm;
  int i,o,s = EPSILON0;
  if (strcmp(original,substitute) == 0)
      return(net);
  if ((o = sigma_find(original, net->sigma)) == -1) {
//fprintf(stderr, "\nSymbol '%s' not found in network!\n", original);
return(net);
  }
  if (strcmp(substitute,"0") == 0)
      s = EPSILON0;
  else if (substitute != NULL((void*)0) && (s = sigma_find(substitute, net->sigma)) == -1) {
      s = sigma_add(substitute, net->sigma);
  }
  for (i=0, fsm = net->states; (fsm+i)->state_no != -1; i++) {
if ((fsm+i)->in == o) {
   (fsm+i)->in = s;
      }
if ((fsm+i)->out == o) {
   (fsm+i)->out = s;
      }
  }
  net->sigma = sigma_remove(original, net->sigma);
  sigma_sort(net);
  fsm_update_flags(net, NO0, NO0, NO0, NO0, NO0, NO0);
  sigma_cleanup(net,0);
  /* if s = epsilon */
  net->is_minimized = NO0;
  return(fsm_determinize(net));
1753}

1755struct fsm *fsm_cross_product(struct fsm *net1, struct fsm *net2) {
int i, a, b, current_state, current_start, current_final, target_number, symbol1, symbol2, epsilon = 0, unknown = 0;
struct fsm_state *machine_a, *machine_b, *fsm;
struct state_arr *point_a, *point_b;
struct triplethash *th;

/* Perform a cross product by running two machines in parallel */
/* The approach here allows a state to stay, creating a a:0 or 0:b transition */
/* with the a/b-state waiting, and the arc going to {a,stay} or {stay,b} */
/* the wait maneuver is only possible if the waiting state is final */

/* For the rewrite rules compilation, a different cross-product is used:  */
/* rewrite_cp() synchronizes A and B as long as possible to get a unique  */
/* output match for each cross product.                                   */

/* This behavior where we postpone zeroes on either side and perform */
/* and equal length cross-product as long as possible and never intermix */
/* ?:0 and 0:? arcs (i.e. we keep both machines synchronized as long as possible */
/* can be done by [A .x. B] & ?:?* [?:0*|0:?*] at the cost of possibly */
/* up to three times larger transducers. */
/* This is very similar to the idea in "tristate composition" in fsm_compose() */

/* This function is only used for explicit cross products */
/* such as a:b or A.x.B, etc.  In rewrite rules, we use rewrite_cp() */

net1 = fsm_minimize(net1);
net2 = fsm_minimize(net2);

fsm_merge_sigma(net1, net2);

fsm_count(net1);
fsm_count(net2);

machine_a = net1->states;
machine_b = net2->states;

/* new state 0 = {0,0} */

STACK_2_PUSH(0,0)int_stack_push(0); int_stack_push(0);;

th = triplet_hash_init();
triplet_hash_insert(th, 0, 0, 0);

fsm_state_init(sigma_max(net1->sigma));

point_a = init_state_pointers(machine_a);
point_b = init_state_pointers(machine_b);

while (!int_stack_isempty()) {

 /* Get a pair of states to examine */

  a = int_stack_pop();
  b = int_stack_pop();

 /* printf("Treating pair: {%i,%i}\n",a,b); */

  current_state = triplet_hash_find(th, a, b, 0);
  current_start = (((point_a+a)->start == 1) && ((point_b+b)->start == 1)) ? 1 : 0;
  current_final = (((point_a+a)->final == 1) && ((point_b+b)->final == 1)) ? 1 : 0;

  fsm_state_set_current_state(current_state, current_final, current_start);

  for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a  ; machine_a++) {
    for (machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {

if ((machine_a->target == -1) && (machine_b->target == -1)) {
 continue;
}
if ((machine_a->target == -1) && (machine_a->final_state == 0)) {
 continue;
}
if ((machine_b->target == -1) && (machine_b->final_state == 0)) {
 continue;
}
/* Main check */
if (!((machine_a->target == -1) || (machine_b->target == -1))) {
   if ((target_number = triplet_hash_find(th, machine_a->target, machine_b->target, 0)) == -1) {
            STACK_2_PUSH(machine_b->target, machine_a->target)int_stack_push(machine_b->target); int_stack_push(machine_a
->target);;
            target_number = triplet_hash_insert(th, machine_a->target, machine_b->target, 0);
 }
 symbol1 = machine_a->in;
 symbol2 = machine_b->in;
 if (symbol1 == IDENTITY2 && symbol2 != IDENTITY2)
   symbol1 = UNKNOWN1;
 if (symbol2 == IDENTITY2 && symbol1 != IDENTITY2)
   symbol2 = UNKNOWN1;

        fsm_state_add_arc(current_state, symbol1, symbol2, target_number, current_final, current_start);
 /* @:@ -> @:@ and also ?:? */
 if ((machine_a->in == IDENTITY2) && (machine_b->in == IDENTITY2)) {
            fsm_state_add_arc(current_state, UNKNOWN1, UNKNOWN1, target_number, current_final, current_start);
 }
}
if (machine_a->final_state == 1 && machine_b->target != -1) {

 /* Add 0:b i.e. stay in state A */
   if ((target_number = triplet_hash_find(th, machine_a->state_no, machine_b->target, 0)) == -1) {
STACK_2_PUSH(machine_b->target, machine_a->state_no)int_stack_push(machine_b->target); int_stack_push(machine_a
->state_no);;
target_number = triplet_hash_insert(th, machine_a->state_no, machine_b->target, 0);
   }
 /* @:0 becomes ?:0 */
 symbol2 = machine_b->in == IDENTITY2 ? UNKNOWN1 : machine_b->in;
        fsm_state_add_arc(current_state, EPSILON0, symbol2, target_number, current_final, current_start);
}

if (machine_b->final_state == 1 && machine_a->target != -1) {

 /* Add a:0 i.e. stay in state B */
   if ((target_number = triplet_hash_find(th, machine_a->target, machine_b->state_no, 0)) == -1) {
            STACK_2_PUSH(machine_b->state_no, machine_a->target)int_stack_push(machine_b->state_no); int_stack_push(machine_a
->target);;
            target_number = triplet_hash_insert(th, machine_a->target, machine_b->state_no, 0);
 }
 /* @:0 becomes ?:0 */
 symbol1 = machine_a->in == IDENTITY2 ? UNKNOWN1 : machine_a->in;
        fsm_state_add_arc(current_state, symbol1, EPSILON0, target_number, current_final, current_start);
}
    }
  }
  /* Check arctrack */
  fsm_state_end_state();
}

free(net1->states);
fsm_state_close(net1);

for (i=0, fsm = net1->states; (fsm+i)->state_no != -1; i++) {
    if (((fsm+i)->in == EPSILON0) || ((fsm+i)->out == EPSILON0))
        epsilon = 1;
    if (((fsm+i)->in == UNKNOWN1) || ((fsm+i)->out == UNKNOWN1))
        unknown = 1;
}
if (epsilon == 1) {
    if (sigma_find_number(EPSILON0, net1->sigma) == -1) {
        sigma_add_special(EPSILON0, net1->sigma);
    }
}
if (unknown == 1) {
    if (sigma_find_number(UNKNOWN1, net1->sigma) == -1) {
        sigma_add_special(UNKNOWN1, net1->sigma);
    }
}
free(point_a);
free(point_b);
fsm_destroy(net2);
triplet_hash_free(th);
return(fsm_coaccessible(net1));
1902}

1904struct fsm *fsm_precedes(struct fsm *net1, struct fsm *net2) {
  return(fsm_complement(fsm_minimize(fsm_contains(fsm_minimize(fsm_concat(fsm_minimize(fsm_copy(net2)),fsm_concat(fsm_universal(),fsm_minimize(fsm_copy(net1)))))))));
1906}

1908struct fsm *fsm_follows(struct fsm *net1, struct fsm *net2) {
  return(fsm_complement(fsm_minimize(fsm_contains(fsm_minimize(fsm_concat(fsm_minimize(fsm_copy(net1)),fsm_concat(fsm_universal(),fsm_minimize(fsm_copy(net2)))))))));
1910}

1912struct fsm *fsm_unflatten(struct fsm *net, char *epsilon_sym, char *repeat_sym) {
  int a, b, current_state, current_start, current_final, target_number, epsilon, repeat, in, out;
  struct fsm_state *even_state, *odd_state;
  struct state_arr *point_a;
  struct triplethash *th;

  fsm_minimize(net);
  fsm_count(net);

  epsilon = sigma_find(epsilon_sym, net->sigma);
  repeat = sigma_find(repeat_sym, net->sigma);

  even_state = net->states;

  /* new state 0 = {0,0} */

  STACK_2_PUSH(0,0)int_stack_push(0); int_stack_push(0);;

  th = triplet_hash_init();
  triplet_hash_insert(th, 0, 0, 0);

  fsm_state_init(sigma_max(net->sigma));

  point_a = init_state_pointers(even_state);

  while (!int_stack_isempty()) {

/* Get a pair of states to examine */

a = int_stack_pop();
a = int_stack_pop();

/* printf("Treating pair: {%i,%i}\n",a,b); */

current_state = triplet_hash_find(th, a, a, 0);
current_start = ((point_a+a)->start == 1) ? 1 : 0;
current_final = ((point_a+a)->final == 1) ? 1 : 0;

fsm_state_set_current_state(current_state, current_final, current_start);

for (even_state = (point_a+a)->transitions; even_state->state_no == a; even_state++) {
   if (even_state->target == -1) {
continue;
   }
   in = even_state->in;
   b = even_state->target;
   for (odd_state = (point_a+b)->transitions; odd_state->state_no == b; odd_state++) {
if (odd_state->target == -1) {
    continue;
}
if ((target_number = triplet_hash_find(th, odd_state->target, odd_state->target, 0)) == -1) {
    STACK_2_PUSH(odd_state->target, odd_state->target)int_stack_push(odd_state->target); int_stack_push(odd_state
->target);;
    target_number = triplet_hash_insert(th, odd_state->target, odd_state->target, 0);
}
in = even_state->in;
out = odd_state->in;
if (out == repeat) {
    out = in;
} else if (in == IDENTITY2 || out == IDENTITY2) {
    in = in == IDENTITY2 ? UNKNOWN1 : in;
    out = out == IDENTITY2 ? UNKNOWN1 : out;
}
if (in == epsilon) {
    in = EPSILON0;
}
if (out == epsilon) {
    out = EPSILON0;
}
fsm_state_add_arc(current_state, in, out, target_number, current_final, current_start);
   }
}
fsm_state_end_state();
  }
  free(net->states);
  fsm_state_close(net);
  free(point_a);
  triplet_hash_free(th);
  return(net);
1990}


1993struct fsm *fsm_shuffle(struct fsm *net1, struct fsm *net2) {
int a, b, current_state, current_start, current_final, target_number;
struct fsm_state *machine_a, *machine_b;
struct state_arr *point_a, *point_b;
struct triplethash *th;

/* Shuffle A and B by making alternatively A move and B stay at each or */
/* vice versa at each step */

fsm_minimize(net1);
fsm_minimize(net2);

fsm_merge_sigma(net1, net2);

fsm_count(net1);
fsm_count(net2);

machine_a = net1->states;
machine_b = net2->states;

/* new state 0 = {0,0} */

STACK_2_PUSH(0,0)int_stack_push(0); int_stack_push(0);;

th = triplet_hash_init();
triplet_hash_insert(th, 0, 0, 0);

fsm_state_init(sigma_max(net1->sigma));

point_a = init_state_pointers(machine_a);
point_b = init_state_pointers(machine_b);

while (!int_stack_isempty()) {

 /* Get a pair of states to examine */

  a = int_stack_pop();
  b = int_stack_pop();

 /* printf("Treating pair: {%i,%i}\n",a,b); */

  current_state = triplet_hash_find(th, a, b, 0);
  current_start = (((point_a+a)->start == 1) && ((point_b+b)->start == 1)) ? 1 : 0;
  current_final = (((point_a+a)->final == 1) && ((point_b+b)->final == 1)) ? 1 : 0;

  fsm_state_set_current_state(current_state, current_final, current_start);

  /* Follow A, B stays */
  for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a  ; machine_a++) {
if (machine_a->target == -1) {
 continue;
}
if ((target_number = triplet_hash_find(th, machine_a->target, b, 0)) == -1) {
        STACK_2_PUSH(b, machine_a->target)int_stack_push(b); int_stack_push(machine_a->target);;
 target_number = triplet_hash_insert(th, machine_a->target, b, 0);
}

      fsm_state_add_arc(current_state, machine_a->in, machine_a->out, target_number, current_final, current_start);
  }

  /* Follow B, A stays */
    for (machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {

if (machine_b->target == -1) {
 continue;
}

if ((target_number = triplet_hash_find(th, a, machine_b->target, 0)) == -1) {
            STACK_2_PUSH(machine_b->target, a)int_stack_push(machine_b->target); int_stack_push(a);;
            target_number = triplet_hash_insert(th, a, machine_b->target, 0);
 }
        fsm_state_add_arc(current_state, machine_b->in, machine_b->out, target_number, current_final, current_start);
    }

    /* Check arctrack */
    fsm_state_end_state();
}

free(net1->states);
fsm_state_close(net1);
free(point_a);
free(point_b);
fsm_destroy(net2);
triplet_hash_free(th);
return(net1);
2078}

2080int fsm_equivalent(struct fsm *net1, struct fsm *net2) {
  /* Test path equivalence of two FSMs by traversing both in parallel */
  int a, b, matching_arc, equivalent;
  struct fsm_state *machine_a, *machine_b;
  struct state_arr *point_a, *point_b;
  struct triplethash *th;

  fsm_merge_sigma(net1, net2);

  fsm_count(net1);
  fsm_count(net2);

  machine_a = net1->states;
  machine_b = net2->states;

  equivalent = 0;
  /* new state 0 = {0,0} */
  STACK_2_PUSH(0,0)int_stack_push(0); int_stack_push(0);;

  th = triplet_hash_init();
  triplet_hash_insert(th, 0, 0, 0);

  point_a = init_state_pointers(machine_a);
  point_b = init_state_pointers(machine_b);

  while (!int_stack_isempty()) {

/* Get a pair of states to examine */

a = int_stack_pop();
b = int_stack_pop();

if ((point_a+a)->final != (point_b+b)->final) {
   goto not_equivalent;
}
/* Check that all arcs in A have matching arc in B, push new state pair on stack */
for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a  ; machine_a++) {
   if (machine_a->target == -1) {
break;
   }
   matching_arc = 0;
   for (machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {
if (machine_b->target == -1) {
    break;
}
if (machine_a->in == machine_b->in && machine_a->out == machine_b->out) {
    matching_arc = 1;
    if ((triplet_hash_find(th, machine_a->target, machine_b->target, 0)) == -1) {
	STACK_2_PUSH(machine_b->target, machine_a->target)int_stack_push(machine_b->target); int_stack_push(machine_a
->target);;
	triplet_hash_insert(th, machine_a->target, machine_b->target, 0);
    }
    break;
}
   }
   if (matching_arc == 0) {
goto not_equivalent;
   }
}
for (machine_b = (point_b+b)->transitions; machine_b->state_no == b ; machine_b++) {
   if (machine_b->target == -1) {
break;
   }
   matching_arc = 0;
   for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a  ; machine_a++) {
if (machine_a->in == machine_b->in && machine_a->out == machine_b->out) {
    matching_arc = 1;
    break;
}
   }
   if (matching_arc == 0) {
goto not_equivalent;
   }
}
  }
  equivalent = 1;
not_equivalent:
  fsm_destroy(net1);
  fsm_destroy(net2);
  free(point_a);
  free(point_b);
  triplet_hash_free(th);
  return(equivalent);
2162}


2165struct fsm *fsm_minus(struct fsm *net1, struct fsm *net2) {
  int a, b, current_state, current_start, current_final, target_number, b_has_trans, btarget, statecount;
  struct fsm_state *machine_a, *machine_b;
  struct state_arr *point_a, *point_b;
  struct triplethash *th;
  statecount = 0;

  net1 = fsm_minimize(net1);
  net2 = fsm_minimize(net2);

  fsm_merge_sigma(net1, net2);

  fsm_count(net1);
  fsm_count(net2);

  machine_a = net1->states;
  machine_b = net2->states;

  /* new state 0 = {1,1} */

  int_stack_clear();
  STACK_2_PUSH(1,1)int_stack_push(1); int_stack_push(1);;

  th = triplet_hash_init();
  triplet_hash_insert(th, 1, 1, 0);

  point_a = init_state_pointers(machine_a);
  point_b = init_state_pointers(machine_b);

  fsm_state_init(sigma_max(net1->sigma));

while (!int_stack_isempty()) {
    statecount++;
    /* Get a pair of states to examine */

    a = int_stack_pop();
    b = int_stack_pop();

    current_state = triplet_hash_find(th, a, b, 0);
    a--;
    b--;

    if (b == -1) {
        current_start = 0;
        current_final = (point_a+a)->final;
    } else {
        current_start = (a == 0 && b == 0) ? 1 : 0;
        current_final = (((point_a+a)->final == 1) && ((point_b+b)->final == 0)) ? 1 : 0;
    }

    fsm_state_set_current_state(current_state, current_final, current_start);

    for (machine_a = (point_a+a)->transitions ; machine_a->state_no == a  ; machine_a++) {
        if (machine_a->target == -1) {
            break;
            continue;
        }
        if (b == -1) {
            /* b is dead */
            if ((target_number = triplet_hash_find(th, (machine_a->target)+1, 0, 0)) == -1) {
                STACK_2_PUSH(0, (machine_a->target)+1)int_stack_push(0); int_stack_push((machine_a->target)+1);;
                target_number = triplet_hash_insert(th, (machine_a->target)+1, 0, 0);
            }
        } else {
            /* b is alive */
            b_has_trans = 0;
            for (machine_b = (point_b+b)->transitions ; machine_b->state_no == b ; machine_b++) {
                if (machine_a->in == machine_b->in && machine_a->out == machine_b->out) {
                    b_has_trans = 1;
                    btarget = machine_b->target;
                    break;
                }
            }
            if (b_has_trans) {
                if ((target_number = triplet_hash_find(th, (machine_a->target)+1, btarget+1, 0)) == -1) {
                    STACK_2_PUSH(btarget+1, (machine_a->target)+1)int_stack_push(btarget+1); int_stack_push((machine_a->target
)+1);;
      target_number = triplet_hash_insert(th, (machine_a->target)+1, (machine_b->target)+1, 0);
                }
            } else {
                /* b is dead */
                if ((target_number = triplet_hash_find(th, (machine_a->target)+1, 0, 0)) == -1) {
                    STACK_2_PUSH(0, (machine_a->target)+1)int_stack_push(0); int_stack_push((machine_a->target)+1);;
      target_number = triplet_hash_insert(th, (machine_a->target)+1, 0, 0);
                }
            }
        }
        fsm_state_add_arc(current_state, machine_a->in, machine_a->out, target_number, current_final, current_start);
    }
    fsm_state_end_state();
}

free(net1->states);
fsm_state_close(net1);
free(point_a);
free(point_b);
fsm_destroy(net2);
triplet_hash_free(th);
return(fsm_minimize(net1));
2263}

2265struct fsm *fsm_contains(struct fsm *net) {
/* [?* A ?*] */
struct fsm *net2;

net2 = fsm_concat(fsm_concat(fsm_universal(),net),fsm_universal());
return(net2);
2271}

2273struct fsm *fsm_universal() {
  struct fsm *net;
  int s;
  net = fsm_create("");
  fsm_update_flags(net, YES1, YES1, YES1, YES1, NO0, NO0);
  net->states = malloc(sizeof(struct fsm_state)*2);
  s = sigma_add_special(IDENTITY2,net->sigma);
  add_fsm_arc(net->states, 0, 0, s, s, 0, 1, 1);
  add_fsm_arc(net->states, 1, -1, -1, -1, -1, -1, -1);
  net->arccount = 1;
  net->statecount = 1;
  net->linecount = 2;
  net->finalcount = 1;
  net->pathcount = PATHCOUNT_CYCLIC-1;
  return(net);
2288}

2290struct fsm *fsm_contains_one(struct fsm *net) {
/* $A - $[[?+ A ?* & A ?*] | [A ?+ & A]] */
  struct fsm *ret;
  ret = fsm_minus(fsm_contains(fsm_copy(net)),fsm_contains(fsm_union(fsm_intersect(fsm_concat(fsm_kleene_plus(fsm_identity()),fsm_concat(fsm_copy(net),fsm_universal())) , fsm_concat(fsm_copy(net),fsm_universal())),fsm_intersect(fsm_concat(fsm_copy(net),fsm_kleene_plus(fsm_identity())), fsm_copy(net)))));
  fsm_destroy(net);
  return(ret);
2296}

2298struct fsm *fsm_contains_opt_one(struct fsm *net) {
/* $.A | ~$A */
  struct fsm *ret;
  ret = fsm_union(fsm_contains_one(fsm_copy(net)),fsm_complement(fsm_contains(fsm_copy(net))));
  fsm_destroy(net);
  return(ret);
2304}

2306struct fsm *fsm_simple_replace(struct fsm *net1, struct fsm *net2) {
/* [~[?* [A-0] ?*] [A.x.B]]* ~[?* [A-0] ?*] */

  struct fsm *UPlus, *ret;
  UPlus = fsm_minimize(fsm_kleene_plus(fsm_identity()));
  ret = fsm_concat(fsm_minimize(fsm_kleene_star(fsm_minimize(fsm_concat(fsm_complement(fsm_minimize(fsm_concat(fsm_concat(fsm_universal(),fsm_minimize(fsm_intersect(fsm_copy(net1),fsm_copy(UPlus)))),fsm_universal()))),fsm_minimize(fsm_cross_product(fsm_copy(net1),fsm_copy(net2))))))),fsm_minimize(fsm_complement(fsm_minimize(fsm_concat(fsm_concat(fsm_universal(), fsm_intersect(fsm_copy(net1),fsm_copy(UPlus))),fsm_universal())))));
  fsm_destroy(net1);
  fsm_destroy(net2);
  fsm_destroy(UPlus);
  return(ret);
2316}

2318struct fsm *fsm_priority_union_upper(struct fsm *net1, struct fsm *net2) {
  /* A .P. B = A | [~[A.u] .o. B] */
  struct fsm *ret;
  ret = fsm_union(fsm_copy(net1),fsm_compose(fsm_complement(fsm_upper(fsm_copy(net1))),net2));
  fsm_destroy(net1);
  return(ret);
2324}

2326struct fsm *fsm_priority_union_lower(struct fsm *net1, struct fsm *net2) {
  /* A .p. B = A | B .o. ~[A.l] */
  struct fsm *ret;
  ret = fsm_union(fsm_copy(net1),fsm_compose(net2,fsm_complement(fsm_lower(fsm_copy(net1)))));
  fsm_destroy(net1);
  return(ret);
2332}

2334struct fsm *fsm_lenient_compose(struct fsm *net1, struct fsm *net2) {
  /* A .O. B = [A .o. B] .P. B */
  struct fsm *ret;
  ret = fsm_priority_union_upper(fsm_compose(fsm_copy(net1),net2),fsm_copy(net1));
  fsm_destroy(net1);
  return(ret);
2340}

2342struct fsm *fsm_term_negation(struct fsm *net1) {
  return(fsm_intersect(fsm_identity(),fsm_complement(net1)));
2344}

2346struct fsm *fsm_quotient_interleave(struct fsm *net1, struct fsm *net2) {
  /* A/\/B = The set of strings you can interleave in B and get a string from A */
  /* [B/[x \x* x] & A/x .o. [[[\x]:0]* (x:0 \x* x:0)]*].l */
  struct fsm *Result;
  Result = fsm_lower(fsm_compose(fsm_intersect(fsm_ignore(net2,fsm_concat(fsm_symbol("@>@"),fsm_concat(fsm_kleene_star(fsm_term_negation(fsm_symbol("@>@"))),fsm_symbol("@>@"))),OP_IGNORE_ALL1),fsm_ignore(net1,fsm_symbol("@>@"),OP_IGNORE_ALL1)),fsm_kleene_star(fsm_concat(fsm_kleene_star(fsm_cross_product(fsm_term_negation(fsm_symbol("@>@")),fsm_empty_string())),fsm_optionality(fsm_concat(fsm_cross_product(fsm_symbol("@>@"),fsm_empty_string()),fsm_concat(fsm_kleene_star(fsm_term_negation(fsm_symbol("@>@"))),fsm_cross_product(fsm_symbol("@>@"),fsm_empty_string()))))))));

  Result->sigma = sigma_remove("@>@",Result->sigma);
  /* Could clean up sigma */
  return(Result);
2355}

2357struct fsm *fsm_quotient_left(struct fsm *net1, struct fsm *net2) {
  /* A\\\B = [B .o. A:0 ?*].l; */
  /* A\\\B = the set of suffixes you can add to A to get a string in B */
  struct fsm *Result;
  Result = fsm_lower(fsm_compose(net2,fsm_concat(fsm_cross_product(net1,fsm_empty_string()),fsm_universal())));
  return(Result);
2363}

2365struct fsm *fsm_quotient_right(struct fsm *net1, struct fsm *net2) {
  struct fsm *Result;

  /* A///B = [A .o. ?* B:0].l; */
  /* A///B = the set of prefixes you can add to B to get strings in A */
  Result = fsm_lower(fsm_compose(net1, fsm_concat(fsm_universal(),fsm_cross_product(net2,fsm_empty_string()))));
  return(Result);
2372}

2374struct fsm *fsm_ignore(struct fsm *net1, struct fsm *net2, int operation) {
struct fsm_state *fsm1, *fsm2, *new_fsm;
struct fsm *Result;
short *handled_states1, *handled_states2;
int i, j, k, state_add_counter = 0, malloc_size, splices = 0, returns, target, splice_size, start_splice, states1, states2, lines1, lines2, *return_state;

net1 = fsm_minimize(net1);
net2 = fsm_minimize(net2);

if (fsm_isempty(net2)) {
    fsm_destroy(net2);
    return(net1);
}
fsm_merge_sigma(net1, net2);

fsm_count(net1);
fsm_count(net2);

states1 = net1->statecount;
states2 = net2->statecount;
lines1 = net1->linecount;
lines2 = net2->linecount;
fsm1 = net1->states;
fsm2 = net2->states;

if (operation == OP_IGNORE_INTERNAL2) {
  Result = fsm_lower(fsm_compose(fsm_ignore(fsm_copy(net1),fsm_symbol("@i<@"),OP_IGNORE_ALL1),fsm_compose(fsm_complement(fsm_union(fsm_concat(fsm_symbol("@i<@"),fsm_universal()),fsm_concat(fsm_universal(),fsm_symbol("@i<@")))),fsm_simple_replace(fsm_symbol("@i<@"),fsm_copy(net2)))));
  Result->sigma = sigma_remove("@i<@",Result->sigma);
  fsm_destroy(net1);
  fsm_destroy(net2);
  return(Result);
}

malloc_size = lines1 + (states1 * (lines2 + net2->finalcount + 1));
new_fsm = malloc(sizeof(struct fsm_state)*(malloc_size+1));

/* Mark if a state has been handled with ignore */
handled_states1 = malloc(sizeof(short)*states1);
handled_states2 = malloc(sizeof(short)*states2);

/* Mark which ignores return to which state */
return_state = malloc(sizeof(int)*states1);
splice_size = states2;
start_splice = states1;
for (k=0; k<states1; k++)
  *(handled_states1+k) = 0;

for (i=0, j=0; (fsm1+i)->state_no != -1; i++) {
  if (*(handled_states1+(fsm1+i)->state_no) == 0) {
    target =  start_splice + splices * splice_size;
    add_fsm_arc(new_fsm, j, (fsm1+i)->state_no, EPSILON0, EPSILON0, target, (fsm1+i)->final_state, (fsm1+i)->start_state);
    *(return_state+splices) = (fsm1+i)->state_no;
    *(handled_states1+(fsm1+i)->state_no) = 1;
    j++;
    splices++;
    if ((fsm1+i)->in != -1) {
add_fsm_arc(new_fsm, j, (fsm1+i)->state_no, (fsm1+i)->in, (fsm1+i)->out, (fsm1+i)->target, (fsm1+i)->final_state, (fsm1+i)->start_state);
j++;
    }
  } else {
    add_fsm_arc(new_fsm, j, (fsm1+i)->state_no, (fsm1+i)->in, (fsm1+i)->out, (fsm1+i)->target, (fsm1+i)->final_state, (fsm1+i)->start_state);
    j++;
  }
}

/* Add a sequence of fsm2s at the end, with arcs back to the appropriate states */

state_add_counter = start_splice;

for (returns = 0; splices>0; splices--, returns++) {
  /* Zero handled return arc states */

  for (k=0; k<states2; k++)
*(handled_states2+k) = 0;

  for (i=0; (fsm2+i)->state_no != -1; i++) {
    if ((fsm2+i)->final_state == 1 && *(handled_states2+(fsm2+i)->state_no) == 0) {
add_fsm_arc(new_fsm, j, (fsm2+i)->state_no + state_add_counter, EPSILON0, EPSILON0, *(return_state+returns), 0, 0);
j++;
*(handled_states2+(fsm2+i)->state_no) = 1;
if ((fsm2+i)->target != -1) {
 add_fsm_arc(new_fsm, j, (fsm2+i)->state_no + state_add_counter, (fsm2+i)->in, (fsm2+i)->out , (fsm2+i)->target + state_add_counter, 0, 0);
 j++;
}
    } else {
add_fsm_arc(new_fsm, j, (fsm2+i)->state_no + state_add_counter, (fsm2+i)->in, (fsm2+i)->out, (fsm2+i)->target + state_add_counter, 0, 0);
j++;
    }
  }
  state_add_counter = state_add_counter + states2;
}

add_fsm_arc(new_fsm, j, -1, -1, -1, -1, -1, -1);
free(handled_states1);
free(handled_states2);
free(return_state);
free(net1->states);
fsm_destroy(net2);
net1->states = new_fsm;
fsm_update_flags(net1, NO0, NO0, NO0, NO0, NO0, NO0);
fsm_count(net1);
return(net1);
2476}

2478/* Remove those symbols from sigma that have the same distribution as IDENTITY */

2480void fsm_compact(struct fsm *net) {
  struct checktable {
      int state_no;
      int target;
  } *checktable;

  struct fsm_state *fsm;
  struct sigma *sig, *sigprev, *sign;
  _Bool *potential;
  int i, j, prevstate, numsymbols, in, out, state, target, removable;

  fsm = net->states;
  numsymbols = sigma_max(net->sigma);

  potential = malloc(sizeof(_Bool)*(numsymbols+1));
  checktable = malloc(sizeof(struct checktable)*(numsymbols+1));

  for (i=0; i <= numsymbols; i++) {
      *(potential+i) =  1;
      (checktable+i)->state_no = -1;
      (checktable+i)->target = -1;
  }
  /* For consistency reasons, can't remove symbols longer than 1 */
  /* since @ and ? only match utf8 symbols of length 1           */

  for (sig = net->sigma; sig != NULL((void*)0) && sig->number != -1; sig = sig->next) {
if (utf8strlen(sig->symbol) > 1) {
   *(potential+sig->number) = 0;
}
  }

  prevstate = 0;

  for (i=0;  ; i++) {

      if ((fsm+i)->state_no != prevstate) {
          for (j=3; j<=numsymbols;j++) {
              if ((checktable+j)->state_no != prevstate && (checktable+IDENTITY2)->state_no != prevstate) {
                  continue;
              }
              if ((checktable+j)->target == (checktable+IDENTITY2)->target && (checktable+j)->state_no == (checktable+IDENTITY2)->state_no) {
                  continue;
              }
              *(potential+j) = 0;
          }
      }

      if ((fsm+i)->state_no == -1)
          break;

      in = (fsm+i)->in;
      out = (fsm+i)->out;
      state = (fsm+i)->state_no;
      target = (fsm+i)->target;

      if (in != -1 && out != -1) {
          if (((in == out && in > 2) || in == IDENTITY2)) {
              (checktable+in)->state_no = state;
              (checktable+in)->target = target;
          }
          if (in != out && in > 2) {
              *(potential+in) = 0;
          }
          if (in != out && out > 2) {
              *(potential+out) = 0;
          }
      }
      prevstate = state;
  }
  for (removable = 0, i=3; i <= numsymbols; i++) {
      if (*(potential+i) == 1) {
          removable = 1;
      }

  }
  if (removable == 0) {
      free(potential);
      free(checktable);
      return;
  }
  i = j = 0;
  do {
      in = (fsm+i)->in;

      add_fsm_arc(fsm, j ,(fsm+i)->state_no,(fsm+i)->in,(fsm+i)->out,(fsm+i)->target,(fsm+i)->final_state,(fsm+i)->start_state);
      if (in == -1) {
          i++;
          j++;
      }
      else if (*(potential+in) == 1 && in > 2) {
          i++;
      } else {
          i++;
          j++;
      }
  } while ((fsm+i)->state_no != -1);
  add_fsm_arc(fsm, j ,(fsm+i)->state_no,(fsm+i)->in,(fsm+i)->out,(fsm+i)->target,(fsm+i)->final_state,(fsm+i)->start_state);

  sigprev = NULL((void*)0);
  for (sig = net->sigma; sig != NULL((void*)0) && sig->number != -1; sig = sign) {

      if ((sig->number > 2) && (*(potential+sig->number) == 1)) {
          sigprev->next = sig->next;
          sign = sig->next;
          free(sig->symbol);
          free(sig);
      } else {
          sigprev = sig;
          sign = sig->next;
      }
  }
  free(potential);
  free(checktable);
  sigma_cleanup(net,0);
2594}

2596int fsm_symbol_occurs(struct fsm *net, char *symbol, int side) {
  struct fsm_state *fsm;
  int i, sym;
  sym = sigma_find(symbol, net->sigma);
  if (sym == -1) {
      return 0;
  }
  for (i=0, fsm = net->states; (fsm+i)->state_no != -1; i++) {
      if (side == M_UPPER1 && (fsm+i)->in == sym)
          return 1;
      if (side == M_LOWER2 && (fsm+i)->out == sym)
          return 1;
      if (side == (M_UPPER1 + M_LOWER2) && ( (fsm+i)->in == sym || (fsm+i)->out == sym))
          return 1;
  }
  return 0;
2612}

2614struct fsm *fsm_equal_substrings(struct fsm *net, struct fsm *left, struct fsm *right) {

  /* The algorithm extracts from the lower side all and only those strings where   */
  /* every X occurring in different substrings ... left X right ... is identical.  */

  /* Caveat: there is no reliable termination condition for the loop that extracts */
  /* identities.  This means that if run on languages where there are potentially  */
  /* infinite-length identical delimited substrings, it will not terminate.        */

  /* For example: _eq(l a* r l a* r, l , r) will not terminate.                    */

  /* However, even if the languages occuring between left and right are infinite   */
  /* the algorithm terminates eventually if the the possible combinations of       */
  /* identical substrings is finite in length.                                     */

  /* For example _eq([l a* b r l a b* r]*, l, r) does terminate even though        */
  /* it contains a potentially infinite number of delimited substrings since       */
  /* the maximum length of the possible identical delimited substrings is finite.  */

  /* In this case the above example evaluates to the language [l a b r l a b r]*   */

  /* The algorithm: */
  /* Input: L, left, right */
  /* Output: the language that preserves only those strings in L */
  /*         where X is the same for all left X right sequences  */

  /* 1. mark all instances of left with ... LB and right with RB ... in L   */

  /* 2. split L into Leq and Lbypass                                        */
  /*    where Lbypass are all those strings where LB RB sequences aren't    */
  /*    properly nested (we must have ... LB ... RB ... LB ... RB ... etc.) */
  /*    Lbypass also includes all those with less than two bracketed        */
  /*    instances, since we don't need to check equality if there's only    */
  /*    one bracketed substring.                                            */
  /*    We also remove the auxiliary LB and RB symbols from Lbypass         */

  /* 3. We extract all the possible symbols occurring between LB and RB     */
  /*    from Leq                                                            */

  /* 4. We create the transducer Move from all symbols in (3)               */
  /*    Move = M(sym_1) | ... | M(sym_n)                                    */
  /*    where M(a) is defined as [\LB* LB:a a:LB]* \LB*                     */
  /*    i.e. it rewrites bracketed strings such as "LB a b RB LB a b RB"    */
  /*    to "a LB b RB a LB b RB" in effect moving brackets to the right     */
  /*    one step for a symbol.                                              */

  /* 5. Leq = Cleanup(Leq)                                                  */
  /*    Cleanup removes LB RB sequences and, at the same time filters out   */
  /*    any strings where we find both LB RB and LB X RB where X is not 0.  */
  /*    since we know such sequences could not possibly be identical        */
  /*    Cleanup is implemented by composing Leq with                        */
  /*    \LB* [LB:0 RB:0 \LB*]* | ~$[LB RB]                                  */
  /*    - if the symbol LB does not occur on the lower side of Leq, goto(6) */
  /*    - else Leq = Move(Leq), goto(5)                                     */

  /* 6. Result = L .o. [Leq | Lbypass]                                      */

  int syms;
  struct sigma *sig;
  struct fsm *LB, *RB, *NOLB, *NORB, *InsertBrackets, *RemoveBrackets, *Lbracketed, *NOBR, *BracketFilter, *Lbypass, *Leq, *Labels, *Cleanup, *ThisMove, *ThisSymbol, *Move, *Result, *oldnet;

  oldnet = fsm_copy(net);

  /* LB = "@<eq<@" */
  /* RB = "@>eq>@" */

  LB = fsm_symbol("@<eq<@");
  NOLB = fsm_minimize(fsm_term_negation(fsm_copy(LB)));
  RB = fsm_symbol("@>eq>@");
  NORB = fsm_minimize(fsm_term_negation(fsm_copy(RB)));
  /* NOBR = ~$[LB|RB] */
  NOBR = fsm_minimize(fsm_complement(fsm_contains(fsm_union(fsm_copy(LB),fsm_copy(RB)))));

  sigma_add("@<eq<@", net->sigma);
  sigma_add("@>eq>@", net->sigma);
  sigma_sort(net);

  /* Insert our aux markers into the language                */

  /* InsertBrackets = [~$[L|R] [L 0:LB|0:RB R]]* ~$[L|R];    */

  InsertBrackets = fsm_minimize(fsm_concat(fsm_kleene_star(fsm_concat(fsm_complement(fsm_contains(fsm_union(fsm_copy(left),fsm_copy(right)))),fsm_union(fsm_concat(fsm_copy(left),fsm_cross_product(fsm_empty_string(),fsm_copy(LB))),fsm_concat(fsm_cross_product(fsm_empty_string(),fsm_copy(RB)),fsm_copy(right))))),fsm_complement(fsm_contains(fsm_union(fsm_copy(left),fsm_copy(right))))));


  /* Lbracketed = L .o. InsertBrackets                       */

  Lbracketed = fsm_compose(fsm_copy(net), InsertBrackets);

  /* Filter out improper nestings, or languages with less than two marker pairs */

  /* BracketFilter = NOBR LB NOBR RB NOBR [LB NOBR RB NOBR]+  */

  BracketFilter = fsm_concat(fsm_copy(NOBR),fsm_concat(fsm_copy(LB),fsm_concat(fsm_copy(NOBR),fsm_concat(fsm_copy(RB),fsm_concat(fsm_copy(NOBR),fsm_kleene_plus(fsm_concat(fsm_copy(LB),fsm_concat(fsm_copy(NOBR),fsm_concat(fsm_copy(RB),fsm_copy(NOBR))))))))));

  /* RemoveBrackets = [LB:0|RB:0|NOBR]*                       */
  /* Lbypass = [Lbracketed .o. ~BracketFilter .o. LB|RB -> 0] */
  /* Leq     = [Lbracketed .o.  BracketFilter]                */

  RemoveBrackets = fsm_kleene_star(fsm_union(fsm_cross_product(fsm_copy(LB),fsm_empty_string()),fsm_union(fsm_cross_product(fsm_copy(RB),fsm_empty_string()),fsm_copy(NOBR))));


  Lbypass = fsm_lower(fsm_compose(fsm_copy(Lbracketed),fsm_compose(fsm_complement(fsm_copy(BracketFilter)),RemoveBrackets)));
  Leq     = fsm_compose(Lbracketed, BracketFilter);

  /* Extract labels from lower side of L */
  /* [Leq .o. [\LB:0* LB:0 \RB* RB:0]* \LB:0*].l */

  Labels = fsm_sigma_pairs_net(fsm_lower(fsm_compose(fsm_copy(Leq),fsm_concat(fsm_kleene_star(fsm_concat(fsm_kleene_star(fsm_cross_product(fsm_copy(NOLB),fsm_empty_string())),fsm_concat(fsm_cross_product(fsm_copy(LB),fsm_empty_string()),fsm_concat(fsm_kleene_star(fsm_copy(NORB)),fsm_cross_product(fsm_copy(RB),fsm_empty_string()))))),fsm_kleene_star(fsm_cross_product(fsm_copy(NOLB),fsm_empty_string()))))));

  /* Cleanup = \LB* [LB:0 RB:0 \LB*]* | ~$[LB RB] */

  Cleanup = fsm_minimize(fsm_union(fsm_concat(fsm_kleene_star(fsm_copy(NOLB)),fsm_kleene_star(fsm_concat(fsm_cross_product(fsm_copy(LB),fsm_empty_string()),fsm_concat(fsm_cross_product(fsm_copy(RB),fsm_empty_string()),fsm_kleene_star(fsm_copy(NOLB)))))),fsm_complement(fsm_contains(fsm_concat(fsm_copy(LB),fsm_copy(RB))))));

  /* Construct the move function */

  Move = fsm_empty_string();

  syms = 0;
  for (sig = Labels->sigma; sig != NULL((void*)0); sig = sig->next) {
      /* Unclear which is faster: the first or the second version */
      /* ThisMove = [\LB* LB:X X:LB]* \LB*       */
      /* ThisMove = [\LB* LB:0 X 0:LB]* \LB*     */
      if (sig->number >= 3) {
          ThisSymbol = fsm_symbol(sig->symbol);
          //ThisMove = fsm_concat(fsm_kleene_star(fsm_concat(fsm_kleene_star(fsm_copy(NOLB)),fsm_concat(fsm_cross_product(fsm_copy(LB),fsm_copy(ThisSymbol)),fsm_cross_product(fsm_copy(ThisSymbol),fsm_copy(LB))))), fsm_kleene_star(fsm_copy(NOLB)));
          ThisMove = fsm_concat(fsm_kleene_star(fsm_concat(fsm_kleene_star(fsm_copy(NOLB)),fsm_concat(fsm_cross_product(fsm_copy(LB),fsm_empty_string()), fsm_concat(fsm_copy(ThisSymbol), fsm_cross_product(fsm_empty_string(),fsm_copy(LB)))))), fsm_kleene_star(fsm_copy(NOLB)));

          Move = fsm_union(Move, ThisMove);
          syms++;
      }
  }
  Move = fsm_minimize(Move);
  if (syms == 0) {
      //printf("no syms");
      fsm_destroy(net);
      return(oldnet);
  }

  /* Move until no bracket symbols remain */
  for (;;) {
      //printf("Zapping\n");
      Leq = fsm_compose(Leq, fsm_copy(Cleanup));
      if (!fsm_symbol_occurs(Leq, "@<eq<@", M_LOWER2))
          break;
      Leq = fsm_compose(Leq, fsm_copy(Move));
      //Leq = fsm_minimize(fsm_compose(Leq, fsm_copy(Move)));
      //        printf("size: %i\n",Leq->statecount);
  }

  /* Result = L .o. [Leq | Lbypass] */
  Result = fsm_minimize(fsm_compose(net, fsm_union(fsm_lower(Leq), Lbypass)));
  sigma_remove("@<eq<@", Result->sigma);
  sigma_remove("@>eq>@", Result->sigma);
  fsm_compact(Result);
  sigma_sort(Result);
  fsm_destroy(oldnet);
  return(Result);
2771}

2773struct fsm *fsm_invert(struct fsm *net) {
struct fsm_state *fsm;
int i, temp;

fsm = net->states;
for (i = 0; (fsm+i)->state_no != -1; i++) {
  temp = (fsm+i)->in;
  (fsm+i)->in = (fsm+i)->out;
  (fsm+i)->out = temp;
}
i = net->arcs_sorted_in;
net->arcs_sorted_in = net->arcs_sorted_out;
net->arcs_sorted_out = i;
return (net);
2787}

2789struct fsm *fsm_sequentialize(struct fsm *net) {
printf("Implementation pending\n");
return(net);
2792}


2795struct fsm *fsm_bimachine(struct fsm *net) {
  printf("implementation pending\n");
  return(net);
2798}

2800/* _leftrewr(L, a:b) does a -> b || .#. L _    */
2801/* _leftrewr(?* L, a:b) does a -> b || L _     */
2802/* works only with single symbols, but is fast */

2804struct fsm *fsm_left_rewr(struct fsm *net, struct fsm *rewr) {
  struct fsm_construct_handle *outh;
  struct fsm_read_handle *inh;
  struct fsm *newnet;
  int i, maxsigma, *sigmatable, currstate, sinkstate, seensource, innum, outnum, relabelin, relabelout, addedsink;

  fsm_merge_sigma(net, rewr);
  relabelin = rewr->states->in;
  relabelout = rewr->states->out;

  inh = fsm_read_init(net);
  sinkstate = fsm_get_num_states(inh);
  outh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(outh, net->sigma);
  maxsigma = sigma_max(net->sigma);
  maxsigma++;
  sigmatable = malloc(maxsigma * sizeof(int));
  for (i = 0; i < maxsigma; i++) {
*(sigmatable+i) = -1;
  }
  addedsink = 0;
  while ((currstate = fsm_get_next_state(inh)) != -1) {
seensource = 0;
fsm_construct_set_final(outh, currstate);

while (fsm_get_next_state_arc(inh)) {
   innum = fsm_get_arc_num_in(inh);
   outnum = fsm_get_arc_num_out(inh);
   *(sigmatable+innum) = currstate;
   if (innum == relabelin) {
    seensource = 1;
    if (fsm_read_is_final(inh, currstate)) {
	outnum = relabelout;
    }
   }
   fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), fsm_get_arc_target(inh), innum, outnum);
}
for (i = 2; i < maxsigma; i++) {
   if (*(sigmatable+i) != currstate && i != relabelin) {
fsm_construct_add_arc_nums(outh, currstate, sinkstate, i, i);
addedsink = 1;
   }
}
if (seensource == 0) {
   addedsink = 1;
   if (fsm_read_is_final(inh, currstate)) {
fsm_construct_add_arc_nums(outh, currstate, sinkstate, relabelin, relabelout);
   } else {
fsm_construct_add_arc_nums(outh, currstate, sinkstate, relabelin, relabelin);
   }
}
  }
  if (addedsink) {
for (i = 2; i < maxsigma; i++) {
   fsm_construct_add_arc_nums(outh, sinkstate, sinkstate, i, i);
}
fsm_construct_set_final(outh, sinkstate);
  }
  fsm_construct_set_initial(outh, 0);
  fsm_read_done(inh);
  newnet = fsm_construct_done(outh);
  free(sigmatable);
  fsm_destroy(net);
  fsm_destroy(rewr);
  return(newnet);
2869}

2871struct fsm *fsm_add_sink(struct fsm *net, int final) {
  struct fsm_construct_handle *outh;
  struct fsm_read_handle *inh;
  struct fsm *newnet;
  int i, maxsigma, *sigmatable, currstate, sinkstate;

  inh = fsm_read_init(net);
  sinkstate = fsm_get_num_states(inh);
  outh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(outh, net->sigma);
  maxsigma = sigma_max(net->sigma);
  maxsigma++;
  sigmatable = malloc(maxsigma * sizeof(int));
  for (i = 0; i < maxsigma; i++) {
*(sigmatable+i) = -1;
  }
  while ((currstate = fsm_get_next_state(inh)) != -1) {
while (fsm_get_next_state_arc(inh)) {
   fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), fsm_get_arc_target(inh), fsm_get_arc_num_in(inh), fsm_get_arc_num_out(inh));
   *(sigmatable+fsm_get_arc_num_in(inh)) = currstate;
}
for (i = 2; i < maxsigma; i++) {
   if (*(sigmatable+i) != currstate) {
fsm_construct_add_arc_nums(outh, currstate, sinkstate, i, i);
   }
}
  }
  for (i = 2; i < maxsigma; i++) {
fsm_construct_add_arc_nums(outh, sinkstate, sinkstate, i, i);
  }

  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(outh, i);
  }
  if (final == 1) {
fsm_construct_set_final(outh, sinkstate);
  }
  fsm_construct_set_initial(outh, 0);
  fsm_read_done(inh);
  newnet = fsm_construct_done(outh);
  fsm_destroy(net);
  return(newnet);
2913}

2915/* _addfinalloop(L, "#":0) adds "#":0 at all final states */
2916/* _addnonfinalloop(L, "#":0) adds "#":0 at all nonfinal states */
2917/* _addloop(L, "#":0) adds "#":0 at all states */

2919/* Adds loops at finals = 0 nonfinals, finals = 1 finals, finals = 2, all */

2921struct fsm *fsm_add_loop(struct fsm *net, struct fsm *marker, int finals) {
  struct fsm *newnet;
  struct fsm_construct_handle *outh;
  struct fsm_read_handle *inh, *minh;
  int i;

  inh = fsm_read_init(net);
  minh = fsm_read_init(marker);

  outh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(outh, net->sigma);

  while (fsm_get_next_arc(inh)) {
fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), fsm_get_arc_target(inh), fsm_get_arc_num_in(inh), fsm_get_arc_num_out(inh));
  }
  /* Where to put the loops */
  if (finals == 1) {
while ((i = fsm_get_next_final(inh)) != -1) {
   fsm_construct_set_final(outh, i);
   fsm_read_reset(minh);
   while (fsm_get_next_arc(minh)) {
fsm_construct_add_arc(outh, i, i, fsm_get_arc_in(minh), fsm_get_arc_out(minh));
   }
}
  } else if (finals == 0 || finals == 2) {
for (i=0; i < net->statecount; i++) {
   if (finals == 2 || !fsm_read_is_final(inh, i)) {
fsm_read_reset(minh);
while (fsm_get_next_arc(minh)) {
    fsm_construct_add_arc(outh, i, i, fsm_get_arc_in(minh), fsm_get_arc_out(minh));
}
   }
}
  }
  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(outh, i);
  }
  fsm_construct_set_initial(outh, 0);
  fsm_read_done(inh);
  fsm_read_done(minh);
  newnet = fsm_construct_done(outh);
  fsm_destroy(net);
  return(newnet);
2964}

2966/* _marktail(?* L, 0:x) does ~$x .o. [..] -> x || L _ ;   */
2967/* _marktail(?* R.r, 0:x).r does ~$x .o. [..] -> x || _ R */

2969struct fsm *fsm_mark_fsm_tail(struct fsm *net, struct fsm *marker) {
  struct fsm *newnet;
  struct fsm_construct_handle *outh;
  struct fsm_read_handle *inh, *minh;
  int i, *mappings, maxstate, target, newtarget;

  inh = fsm_read_init(net);
  minh = fsm_read_init(marker);

  outh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(outh, net->sigma);

  mappings = calloc(net->statecount, sizeof(int));
  maxstate = net->statecount;

  while (fsm_get_next_arc(inh)) {
target = fsm_get_arc_target(inh);
if (fsm_read_is_final(inh, target)) {
   if (!*(mappings+target)) {
newtarget = maxstate;
*(mappings+target) = newtarget;
fsm_read_reset(minh);
while (fsm_get_next_arc(minh)) {
    fsm_construct_add_arc(outh, newtarget, target, fsm_get_arc_in(minh), fsm_get_arc_out(minh));
}
maxstate++;
   } else {
newtarget = *(mappings+target);
   }
   fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), newtarget, fsm_get_arc_num_in(inh), fsm_get_arc_num_out(inh));
} else {
   fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), target, fsm_get_arc_num_in(inh), fsm_get_arc_num_out(inh));
}
  }
  for (i=0; i < net->statecount; i++) {
fsm_construct_set_final(outh,i);
  }

  fsm_construct_set_initial(outh, 0);
  fsm_read_done(inh);
  fsm_read_done(minh);
  newnet = fsm_construct_done(outh);
  fsm_destroy(net);
  free(mappings);
  return(newnet);
3014}

3016struct fsm *fsm_context_restrict(struct fsm *X, struct fsmcontexts *LR) {

  struct fsm *Var, *Notvar, *UnionL, *UnionP, *Result, *Word;
  struct fsmcontexts *pairs;

  /* [.#. \.#.* .#.]-`[[ [\X* X C X \X*]&~[\X* [L1 X \X* X R1|...|Ln X \X* X Rn] \X*]],X,0] */
  /* Where X = variable symbol */
  /* The above only works if we do the subtraction iff the right hand side contains .#. in */
  /* its alphabet */
  /* A more generic formula is the following: */

  /* `[[[(?) \.#.* (?)] - `[[[\X* X C X \X*] - [\X* [L1 X \X* X R1|...|Ln X \X* X Rn] \X*] ],X,0],.#.,0]; */
  /* Here, the LHS is another way of saying ~[?+ .#. ?+] */

  Var = fsm_symbol("@VARX@");
  Notvar = fsm_minimize(fsm_kleene_star(fsm_term_negation(fsm_symbol("@VARX@"))));

  /* We add the variable symbol to all alphabets to avoid ? mathing it */
  /* which would cause extra nondeterminism */
  sigma_add("@VARX@", X->sigma);
  sigma_sort(X);

  /* Also, if any L or R is undeclared we add 0 */
  for (pairs = LR; pairs != NULL((void*)0); pairs = pairs->next) {
      if (pairs->left == NULL((void*)0)) {
          pairs->left = fsm_empty_string();
      } else {
          sigma_add("@VARX@",pairs->left->sigma);
   sigma_substitute(".#.", "@#@", pairs->left->sigma);
          sigma_sort(pairs->left);
      }
      if (pairs->right == NULL((void*)0)) {
          pairs->right = fsm_empty_string();
      } else {
          sigma_add("@VARX@",pairs->right->sigma);
   sigma_substitute(".#.", "@#@", pairs->right->sigma);
          sigma_sort(pairs->right);
      }
  }

  UnionP = fsm_empty_set();

  for (pairs = LR; pairs != NULL((void*)0) ; pairs = pairs->next) {
      UnionP = fsm_minimize(fsm_union(fsm_minimize(fsm_concat(fsm_copy(pairs->left),fsm_concat(fsm_copy(Var),fsm_concat(fsm_copy(Notvar),fsm_concat(fsm_copy(Var),fsm_copy(pairs->right)))))), UnionP));
  }

  UnionL = fsm_minimize(fsm_concat(fsm_copy(Notvar),fsm_concat(fsm_copy(Var), fsm_concat(fsm_copy(X), fsm_concat(fsm_copy(Var),fsm_copy(Notvar))))));

  Result = fsm_intersect(UnionL, fsm_complement(fsm_concat(fsm_copy(Notvar),fsm_minimize(fsm_concat(fsm_copy(UnionP),fsm_copy(Notvar))))));
  if (sigma_find("@VARX@", Result->sigma) != -1) {
      Result = fsm_complement(fsm_substitute_symbol(Result, "@VARX@","@_EPSILON_SYMBOL_@"));
  } else {
Result = fsm_complement(Result);
  }

  if (sigma_find("@#@", Result->sigma) != -1) {
Word = fsm_minimize(fsm_concat(fsm_symbol("@#@"),fsm_concat(fsm_kleene_star(fsm_term_negation(fsm_symbol("@#@"))),fsm_symbol("@#@"))));
      Result = fsm_intersect(Word, Result);
      Result = fsm_substitute_symbol(Result, "@#@", "@_EPSILON_SYMBOL_@");
  }
  fsm_destroy(UnionP);
  fsm_destroy(Var);
  fsm_destroy(Notvar);
  fsm_destroy(X);
  fsm_clear_contexts(pairs);
  return(Result);
3082}

3084struct fsm *fsm_flatten(struct fsm *net, struct fsm *epsilon) {
  struct fsm *newnet;
  struct fsm_construct_handle *outh;
  struct fsm_read_handle *inh, *eps;
  int i, maxstate, in, out, target;
  char *epssym, *instring, *outstring;

  net = fsm_minimize(net);

  inh = fsm_read_init(net);
  eps = fsm_read_init(epsilon);
  if (fsm_get_next_arc(eps) == -1) {
fsm_destroy(net);
fsm_destroy(epsilon);
return NULL((void*)0);
  }
  epssym = strdup(fsm_get_arc_in(eps));
  fsm_read_done(eps);

  outh = fsm_construct_init(net->name);
  maxstate = net->statecount;

  fsm_construct_copy_sigma(outh, net->sigma);

  while (fsm_get_next_arc(inh)) {
target = fsm_get_arc_target(inh);
in = fsm_get_arc_num_in(inh);
out = fsm_get_arc_num_out(inh);
if (in == EPSILON0 || out == EPSILON0)  {
   instring = fsm_get_arc_in(inh);
   outstring = fsm_get_arc_out(inh);
   if (in == EPSILON0)  { instring = epssym; }
   if (out == EPSILON0) { outstring = epssym; }

   fsm_construct_add_arc(outh, fsm_get_arc_source(inh), maxstate, instring, instring);
   fsm_construct_add_arc(outh, maxstate, target, outstring, outstring);
} else {
   fsm_construct_add_arc_nums(outh, fsm_get_arc_source(inh), maxstate, in, in);
   fsm_construct_add_arc_nums(outh, maxstate, target, out, out);
}
maxstate++;
  }
  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(outh, i);
  }
  while ((i = fsm_get_next_initial(inh)) != -1) {
fsm_construct_set_initial(outh, i);
  }

  fsm_read_done(inh);
  newnet = fsm_construct_done(outh);
  fsm_destroy(net);
  fsm_destroy(epsilon);
  free(epssym);
  return(newnet);
3139}

3141/* Removes IDENTITY and UNKNOWN transitions. If mode = 1, only removes UNKNOWNs */
3142struct fsm *fsm_close_sigma(struct fsm *net, int mode) {
  struct fsm *newnet;
  struct fsm_construct_handle *newh;
  struct fsm_read_handle *inh;
  int i;

  inh = fsm_read_init(net);
  newh = fsm_construct_init(net->name);
  fsm_construct_copy_sigma(newh, net->sigma);

  while (fsm_get_next_arc(inh)) {
if ((fsm_get_arc_num_in(inh) != UNKNOWN1 && fsm_get_arc_num_in(inh) != IDENTITY2 && fsm_get_arc_num_out(inh) != UNKNOWN1 && fsm_get_arc_num_out(inh) != IDENTITY2) || (mode == 1 && fsm_get_arc_num_in(inh) != UNKNOWN1 && fsm_get_arc_num_out(inh) != UNKNOWN1))
   fsm_construct_add_arc_nums(newh, fsm_get_arc_source(inh), fsm_get_arc_target(inh), fsm_get_arc_num_in(inh), fsm_get_arc_num_out(inh));
  }
  while ((i = fsm_get_next_final(inh)) != -1) {
fsm_construct_set_final(newh, i);
  }
  while ((i = fsm_get_next_initial(inh)) != -1) {
fsm_construct_set_initial(newh, i);
  }
  fsm_read_done(inh);
  newnet = fsm_construct_done(newh);
  fsm_destroy(net);
  return(fsm_minimize(newnet));
3166}