Node *
push_negation(Node *n)
{ Node *m;
Assert(n->ntyp == NOT, n->ntyp);
switch (n->lft->ntyp) {
case TRUE:
releasenode(0, n->lft);
n->lft = ZN;
n->ntyp = FALSE;
break;
case FALSE:
releasenode(0, n->lft);
n->lft = ZN;
n->ntyp = TRUE;
break;
case NOT:
m = n->lft->lft;
releasenode(0, n->lft);
n->lft = ZN;
releasenode(0, n);
n = m;
break;
case V_OPER:
n->ntyp = U_OPER;
goto same;
case U_OPER:
n->ntyp = V_OPER;
goto same;
#ifdef NXT
case NEXT:
n->ntyp = NEXT;
n->lft->ntyp = NOT;
n->lft = push_negation(n->lft);
break;
#endif
case AND:
n->ntyp = OR;
goto same;
case OR:
n->ntyp = AND;
same: m = n->lft->rgt;
n->lft->rgt = ZN;
n->rgt = Not(m);
n->lft->ntyp = NOT;
m = n->lft;
n->lft = push_negation(m);
break;
}
return rewrite(n);
}
Node *switchNotTempOper(Node *n, int ntyp, Miscellaneous *miscell, int *cnt, char *uform, int *tl_yychar)
{
Node *m;
m = n;
n = n->lft;
n->ntyp = ntyp;
m->lft = n->lft;
n->lft = push_negation(m, miscell, cnt, uform, tl_yychar);
if (ntyp!=NEXT && ntyp!=WEAKNEXT)
{
n->rgt = Not(n->rgt);
}
return(n);
}
Node *switchNotTempOper(Node *n, int ntyp)
{
Node *m;
m = n;
n = n->lft;
n->ntyp = ntyp;
m->lft = n->lft;
n->lft = push_negation(m);
if (ntyp!=NEXT && ntyp!=WEAKNEXT)
{
n->rgt = Not(n->rgt);
}
return(n);
}
static Node *
tl_factor(void)
{ Node *ptr = ZN;
switch (tl_yychar) {
case '(':
ptr = tl_formula();
if (tl_yychar != ')')
tl_yyerror("expected ')'");
tl_yychar = tl_yylex();
break;
case NOT:
ptr = tl_yylval;
tl_yychar = tl_yylex();
ptr->lft = tl_factor();
if (!ptr->lft)
{ fatal("malformed expression", (char *) 0);
}
ptr = push_negation(ptr);
break;
case ALWAYS:
tl_yychar = tl_yylex();
ptr = tl_factor();
#ifndef NO_OPT
if (ptr->ntyp == FALSE
|| ptr->ntyp == TRUE)
break; /* [] false == false */
if (ptr->ntyp == V_OPER)
{ if (ptr->lft->ntyp == FALSE)
break; /* [][]p = []p */
ptr = ptr->rgt; /* [] (p V q) = [] q */
}
#endif
ptr = tl_nn(V_OPER, False, ptr);
break;
#ifdef NXT
case NEXT:
tl_yychar = tl_yylex();
ptr = tl_factor();
if (ptr->ntyp == TRUE)
break; /* X true = true */
ptr = tl_nn(NEXT, ptr, ZN);
break;
#endif
case CEXPR:
tl_yychar = tl_yylex();
ptr = tl_factor();
if (ptr->ntyp != PREDICATE)
{ tl_yyerror("expected {...} after c_expr");
}
ptr = tl_nn(CEXPR, ptr, ZN);
break;
case EVENTUALLY:
tl_yychar = tl_yylex();
ptr = tl_factor();
#ifndef NO_OPT
if (ptr->ntyp == TRUE
|| ptr->ntyp == FALSE)
break; /* <> true == true */
if (ptr->ntyp == U_OPER
&& ptr->lft->ntyp == TRUE)
break; /* <><>p = <>p */
if (ptr->ntyp == U_OPER)
{ /* <> (p U q) = <> q */
ptr = ptr->rgt;
/* fall thru */
}
#endif
ptr = tl_nn(U_OPER, True, ptr);
break;
case PREDICATE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
case TRUE:
case FALSE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
}
if (!ptr) tl_yyerror("expected predicate");
#if 0
printf("factor: ");
tl_explain(ptr->ntyp);
printf("\n");
#endif
return ptr;
}
Node *
push_negation(Node *n)
{ Node *m;
Assert(n->ntyp == NOT, n->ntyp);
switch (n->lft->ntyp) {
case TRUE:
Debug("!true => false\n");
releasenode(0, n->lft);
n->lft = ZN;
n->ntyp = FALSE;
break;
case FALSE:
Debug("!false => true\n");
releasenode(0, n->lft);
n->lft = ZN;
n->ntyp = TRUE;
break;
case NOT:
Debug("!!p => p\n");
m = n->lft->lft;
releasenode(0, n->lft);
n->lft = ZN;
releasenode(0, n);
n = m;
break;
case V_OPER:
Debug("!(p V q) => (!p U !q)\n");
n->ntyp = U_OPER;
goto same;
case U_OPER:
Debug("!(p U q) => (!p V !q)\n");
n->ntyp = V_OPER;
goto same;
#ifdef NXT
case NEXT:
Debug("!X -> X!\n");
n->ntyp = NEXT;
n->lft->ntyp = NOT;
n->lft = push_negation(n->lft);
break;
#endif
case AND:
Debug("!(p && q) => !p || !q\n");
n->ntyp = OR;
goto same;
case OR:
Debug("!(p || q) => !p && !q\n");
n->ntyp = AND;
same: m = n->lft->rgt;
n->lft->rgt = ZN;
n->rgt = Not(m);
n->lft->ntyp = NOT;
m = n->lft;
n->lft = push_negation(m);
break;
}
return rewrite(n);
}
static Node *bin_simpler(Node *ptr)
{ Node *a, *b;
if (ptr)
switch (ptr->ntyp) {
case U_OPER:
if (ptr->rgt->ntyp == TRUE
|| ptr->rgt->ntyp == FALSE
|| ptr->lft->ntyp == FALSE)
{ ptr = ptr->rgt;
break;
}
if (implies(ptr->lft, ptr->rgt)) /* NEW */
{ ptr = ptr->rgt;
break;
}
if (ptr->lft->ntyp == U_OPER
&& isequal(ptr->lft->lft, ptr->rgt))
{ /* (p U q) U p = (q U p) */
ptr->lft = ptr->lft->rgt;
break;
}
if (ptr->rgt->ntyp == U_OPER
&& implies(ptr->lft, ptr->rgt->lft))
{ /* NEW */
ptr = ptr->rgt;
break;
}
/* X p U X q == X (p U q) */
if (ptr->rgt->ntyp == NEXT
&& ptr->lft->ntyp == NEXT)
{ ptr = tl_nn(NEXT,
tl_nn(U_OPER,
ptr->lft->lft,
ptr->rgt->lft), ZN);
break;
}
/* NEW : F X p == X F p */
if (ptr->lft->ntyp == TRUE &&
ptr->rgt->ntyp == NEXT) {
ptr = tl_nn(NEXT, tl_nn(U_OPER, True, ptr->rgt->lft), ZN);
break;
}
/* NEW : F G F p == G F p */
if (ptr->lft->ntyp == TRUE &&
ptr->rgt->ntyp == V_OPER &&
ptr->rgt->lft->ntyp == FALSE &&
ptr->rgt->rgt->ntyp == U_OPER &&
ptr->rgt->rgt->lft->ntyp == TRUE) {
ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->lft->ntyp != TRUE &&
implies(push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN)), ptr->lft))
{ ptr->lft = True;
break;
}
break;
case V_OPER:
if (ptr->rgt->ntyp == FALSE
|| ptr->rgt->ntyp == TRUE
|| ptr->lft->ntyp == TRUE)
{ ptr = ptr->rgt;
break;
}
if (implies(ptr->rgt, ptr->lft))
{ /* p V p = p */
ptr = ptr->rgt;
break;
}
/* F V (p V q) == F V q */
if (ptr->lft->ntyp == FALSE
&& ptr->rgt->ntyp == V_OPER)
{ ptr->rgt = ptr->rgt->rgt;
break;
}
/* NEW : G X p == X G p */
if (ptr->lft->ntyp == FALSE &&
ptr->rgt->ntyp == NEXT) {
ptr = tl_nn(NEXT, tl_nn(V_OPER, False, ptr->rgt->lft), ZN);
break;
}
/* NEW : G F G p == F G p */
if (ptr->lft->ntyp == FALSE &&
ptr->rgt->ntyp == U_OPER &&
ptr->rgt->lft->ntyp == TRUE &&
ptr->rgt->rgt->ntyp == V_OPER &&
ptr->rgt->rgt->lft->ntyp == FALSE) {
ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->rgt->ntyp == V_OPER
&& implies(ptr->rgt->lft, ptr->lft))
{ ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->lft->ntyp != FALSE &&
implies(ptr->lft,
push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN))))
{ ptr->lft = False;
break;
}
break;
case NEXT:
/* NEW : X G F p == G F p */
if (ptr->lft->ntyp == V_OPER &&
ptr->lft->lft->ntyp == FALSE &&
ptr->lft->rgt->ntyp == U_OPER &&
ptr->lft->rgt->lft->ntyp == TRUE) {
ptr = ptr->lft;
break;
}
/* NEW : X F G p == F G p */
if (ptr->lft->ntyp == U_OPER &&
ptr->lft->lft->ntyp == TRUE &&
ptr->lft->rgt->ntyp == V_OPER &&
ptr->lft->rgt->lft->ntyp == FALSE) {
ptr = ptr->lft;
break;
}
break;
case IMPLIES:
if (implies(ptr->lft, ptr->rgt))
{ ptr = True;
break;
}
ptr = tl_nn(OR, Not(ptr->lft), ptr->rgt);
ptr = rewrite(ptr);
break;
case EQUIV:
if (implies(ptr->lft, ptr->rgt) &&
implies(ptr->rgt, ptr->lft))
{ ptr = True;
break;
}
a = rewrite(tl_nn(AND,
dupnode(ptr->lft),
dupnode(ptr->rgt)));
b = rewrite(tl_nn(AND,
Not(ptr->lft),
Not(ptr->rgt)));
ptr = tl_nn(OR, a, b);
ptr = rewrite(ptr);
break;
case AND:
/* p && (q U p) = p */
if (ptr->rgt->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft))
{ ptr = ptr->lft;
break;
}
if (ptr->lft->ntyp == U_OPER
&& isequal(ptr->lft->rgt, ptr->rgt))
{ ptr = ptr->rgt;
break;
}
/* p && (q V p) == q V p */
if (ptr->rgt->ntyp == V_OPER
&& isequal(ptr->rgt->rgt, ptr->lft))
{ ptr = ptr->rgt;
break;
}
if (ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt))
{ ptr = ptr->lft;
break;
}
/* (p U q) && (r U q) = (p && r) U q*/
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft->rgt))
{ ptr = tl_nn(U_OPER,
tl_nn(AND, ptr->lft->lft, ptr->rgt->lft),
ptr->lft->rgt);
break;
}
/* (p V q) && (p V r) = p V (q && r) */
if (ptr->rgt->ntyp == V_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->rgt->lft, ptr->lft->lft))
{ ptr = tl_nn(V_OPER,
ptr->rgt->lft,
tl_nn(AND, ptr->lft->rgt, ptr->rgt->rgt));
break;
}
/* X p && X q == X (p && q) */
if (ptr->rgt->ntyp == NEXT
&& ptr->lft->ntyp == NEXT)
{ ptr = tl_nn(NEXT,
tl_nn(AND,
ptr->rgt->lft,
ptr->lft->lft), ZN);
break;
}
/* (p V q) && (r U q) == p V q */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt))
{ ptr = ptr->lft;
break;
}
if (isequal(ptr->lft, ptr->rgt) /* (p && p) == p */
|| ptr->rgt->ntyp == FALSE /* (p && F) == F */
|| ptr->lft->ntyp == TRUE /* (T && p) == p */
|| implies(ptr->rgt, ptr->lft))/* NEW */
{ ptr = ptr->rgt;
break;
}
if (ptr->rgt->ntyp == TRUE /* (p && T) == p */
|| ptr->lft->ntyp == FALSE /* (F && p) == F */
|| implies(ptr->lft, ptr->rgt))/* NEW */
{ ptr = ptr->lft;
break;
}
/* NEW : F G p && F G q == F G (p && q) */
if (ptr->lft->ntyp == U_OPER &&
ptr->lft->lft->ntyp == TRUE &&
ptr->lft->rgt->ntyp == V_OPER &&
ptr->lft->rgt->lft->ntyp == FALSE &&
ptr->rgt->ntyp == U_OPER &&
ptr->rgt->lft->ntyp == TRUE &&
ptr->rgt->rgt->ntyp == V_OPER &&
ptr->rgt->rgt->lft->ntyp == FALSE)
{
ptr = tl_nn(U_OPER, True,
tl_nn(V_OPER, False,
tl_nn(AND, ptr->lft->rgt->rgt,
ptr->rgt->rgt->rgt)));
break;
}
/* NEW */
if (implies(ptr->lft,
push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN)))
|| implies(ptr->rgt,
push_negation(tl_nn(NOT, dupnode(ptr->lft), ZN))))
{ ptr = False;
break;
}
break;
case OR:
/* p || (q U p) == q U p */
if (ptr->rgt->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft))
{ ptr = ptr->rgt;
break;
}
/* p || (q V p) == p */
if (ptr->rgt->ntyp == V_OPER
&& isequal(ptr->rgt->rgt, ptr->lft))
{ ptr = ptr->lft;
break;
}
/* (p U q) || (p U r) = p U (q || r) */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == U_OPER
&& isequal(ptr->rgt->lft, ptr->lft->lft))
{ ptr = tl_nn(U_OPER,
ptr->rgt->lft,
tl_nn(OR, ptr->lft->rgt, ptr->rgt->rgt));
break;
}
if (isequal(ptr->lft, ptr->rgt) /* (p || p) == p */
|| ptr->rgt->ntyp == FALSE /* (p || F) == p */
|| ptr->lft->ntyp == TRUE /* (T || p) == T */
|| implies(ptr->rgt, ptr->lft))/* NEW */
{ ptr = ptr->lft;
break;
}
if (ptr->rgt->ntyp == TRUE /* (p || T) == T */
|| ptr->lft->ntyp == FALSE /* (F || p) == p */
|| implies(ptr->lft, ptr->rgt))/* NEW */
{ ptr = ptr->rgt;
break;
}
/* (p V q) || (r V q) = (p || r) V q */
if (ptr->rgt->ntyp == V_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt))
{ ptr = tl_nn(V_OPER,
tl_nn(OR, ptr->lft->lft, ptr->rgt->lft),
ptr->rgt->rgt);
break;
}
/* (p V q) || (r U q) == r U q */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt))
{ ptr = ptr->rgt;
break;
}
/* NEW : G F p || G F q == G F (p || q) */
if (ptr->lft->ntyp == V_OPER &&
ptr->lft->lft->ntyp == FALSE &&
ptr->lft->rgt->ntyp == U_OPER &&
ptr->lft->rgt->lft->ntyp == TRUE &&
ptr->rgt->ntyp == V_OPER &&
ptr->rgt->lft->ntyp == FALSE &&
ptr->rgt->rgt->ntyp == U_OPER &&
ptr->rgt->rgt->lft->ntyp == TRUE)
{
ptr = tl_nn(V_OPER, False,
tl_nn(U_OPER, True,
tl_nn(OR, ptr->lft->rgt->rgt,
ptr->rgt->rgt->rgt)));
break;
}
/* NEW */
if (implies(push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN)),
ptr->lft)
|| implies(push_negation(tl_nn(NOT, dupnode(ptr->lft), ZN)),
ptr->rgt))
{ ptr = True;
break;
}
break;
}
return ptr;
}
static Node *tl_factor(void)
{
Node *ptr = ZN;
switch (tl_yychar)
{
case '(':
ptr = tl_formula();
if (tl_yychar != ')')
tl_yyerror("expected ')'");
tl_yychar = tl_yylex();
goto simpl;
case NOT:
ptr = tl_yylval;
tl_yychar = tl_yylex();
ptr->lft = tl_factor();
ptr = push_negation(ptr);
goto simpl;
case ALWAYS:
ptr = tl_nn(V_OPER, False, ptr);
ptr->time = TimeCon;
tl_yychar = tl_yylex();
ptr->rgt = tl_factor();
if(tl_simp_log)
{ /* must be modified! */
if (ptr->ntyp == V_OPER)
{
if (ptr->lft->ntyp == FALSE)
break; /* [][]p = []p */
ptr = ptr->rgt; /* [] (p V q) = [] q */
}
}
goto simpl;
case NEXT:
ptr = tl_nn(NEXT, ZN, ZN);
ptr->time = TimeCon;
tl_yychar = tl_yylex();
ptr->lft = tl_factor();
goto simpl;
case WEAKNEXT:
ptr = tl_nn(WEAKNEXT, ZN, ZN);
ptr->time = TimeCon;
tl_yychar = tl_yylex();
ptr->lft = tl_factor();
goto simpl;
case EVENTUALLY:
ptr = tl_nn(U_OPER, True, ZN);
ptr->time = TimeCon;
tl_yychar = tl_yylex();
ptr->rgt = tl_factor();
if(tl_simp_log)
{ /* this must be modified */
if (ptr->ntyp == U_OPER && ptr->lft->ntyp == TRUE)
break; /* <><>p = <>p */
if (ptr->ntyp == U_OPER)
{ /* <> (p U q) = <> q */
ptr = ptr->rgt;
/* fall thru */
}
}
/* goto simpl;
case IMPLIES:
ptr = tl_nn(OR, Not(ptr->lft), ptr->rgt);
goto simpl;
case EQUIV:
a = tl_nn(AND,dupnode(ptr->lft),dupnode(ptr->rgt));
b = tl_nn(AND,Not(ptr->lft),Not(ptr->rgt));
ptr = tl_nn(OR, a, b); */
simpl:
if (tl_simp_log)
ptr = bin_simpler(ptr);
break;
case PREDICATE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
case TRUE:
case FALSE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
}
if (!ptr) tl_yyerror("expected predicate");
#if 0
printf("factor: ");
tl_explain(ptr->ntyp);
printf("\n");
#endif
return ptr;
}
static Node *
tl_factor(void)
{ Node *ptr = ZN;
switch (tl_yychar) {
case '(':
ptr = tl_formula();
if (tl_yychar != ')')
tl_yyerror("expected ')'");
tl_yychar = tl_yylex();
goto simpl;
case NOT:
ptr = tl_yylval;
tl_yychar = tl_yylex();
ptr->lft = tl_factor();
ptr = push_negation(ptr);
goto simpl;
case ALWAYS:
tl_yychar = tl_yylex();
ptr = tl_factor();
if(tl_simp_log) {
if (ptr->ntyp == FALSE
|| ptr->ntyp == TRUE)
break; /* [] false == false */
if (ptr->ntyp == V_OPER)
{ if (ptr->lft->ntyp == FALSE)
break; /* [][]p = []p */
ptr = ptr->rgt; /* [] (p V q) = [] q */
}
}
ptr = tl_nn(V_OPER, False, ptr);
goto simpl;
#ifdef NXT
case NEXT:
tl_yychar = tl_yylex();
ptr = tl_factor();
if ((ptr->ntyp == TRUE || ptr->ntyp == FALSE)&& tl_simp_log)
break; /* X true = true , X false = false */
ptr = tl_nn(NEXT, ptr, ZN);
goto simpl;
#endif
case EVENTUALLY:
tl_yychar = tl_yylex();
ptr = tl_factor();
if(tl_simp_log) {
if (ptr->ntyp == TRUE
|| ptr->ntyp == FALSE)
break; /* <> true == true */
if (ptr->ntyp == U_OPER
&& ptr->lft->ntyp == TRUE)
break; /* <><>p = <>p */
if (ptr->ntyp == U_OPER)
{ /* <> (p U q) = <> q */
ptr = ptr->rgt;
/* fall thru */
}
}
ptr = tl_nn(U_OPER, True, ptr);
simpl:
if (tl_simp_log)
ptr = bin_simpler(ptr);
break;
case PREDICATE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
case TRUE:
case FALSE:
ptr = tl_yylval;
tl_yychar = tl_yylex();
break;
}
if (!ptr) tl_yyerror("expected predicate");
#if 0
printf("factor: ");
tl_explain(ptr->ntyp);
printf("\n");
#endif
return ptr;
}
static Node *bin_simpler(Node *ptr, Miscellaneous *miscell, int *cnt, char *uform, int *tl_yychar)
{ Node *a, *b;
if (ptr)
switch (ptr->ntyp) {
case U_OPER:
if (ptr->rgt->ntyp == TRUE
|| ptr->rgt->ntyp == FALSE
|| ptr->lft->ntyp == FALSE)
{ ptr = ptr->rgt;
break;
}
if (implies(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell)) /* NEW */
{ ptr = ptr->rgt;
break;
}
if (ptr->lft->ntyp == U_OPER
&& isequal(ptr->lft->lft, ptr->rgt, cnt, uform, tl_yychar, miscell))
{ /* (p U q) U p = (q U p) */
ptr->lft = ptr->lft->rgt;
break;
}
if (ptr->rgt->ntyp == U_OPER
&& implies(ptr->lft, ptr->rgt->lft, cnt, uform, tl_yychar, miscell))
{ /* NEW */
ptr = ptr->rgt;
break;
}
/* X p U X q == X (p U q) */
if (ptr->rgt->ntyp == NEXT
&& ptr->lft->ntyp == NEXT)
{ ptr = tl_nn(NEXT,
tl_nn(U_OPER,
ptr->lft->lft,
ptr->rgt->lft, miscell), ZN, miscell);
break;
}
/* NEW : F X p == X F p */
if (ptr->lft->ntyp == TRUE &&
ptr->rgt->ntyp == NEXT) {
ptr = tl_nn(NEXT, tl_nn(U_OPER, True, ptr->rgt->lft, miscell), ZN, miscell);
break;
}
/* NEW : F G F p == G F p */
if (ptr->lft->ntyp == TRUE &&
ptr->rgt->ntyp == V_OPER &&
ptr->rgt->lft->ntyp == FALSE &&
ptr->rgt->rgt->ntyp == U_OPER &&
ptr->rgt->rgt->lft->ntyp == TRUE) {
ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->lft->ntyp != TRUE &&
implies(push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN, miscell), miscell, cnt, uform, tl_yychar), ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr->lft = True;
break;
}
break;
case V_OPER:
if (ptr->rgt->ntyp == FALSE
|| ptr->rgt->ntyp == TRUE
|| ptr->lft->ntyp == TRUE)
{ ptr = ptr->rgt;
break;
}
if (implies(ptr->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ /* p V p = p */
ptr = ptr->rgt;
break;
}
/* F V (p V q) == F V q */
if (ptr->lft->ntyp == FALSE
&& ptr->rgt->ntyp == V_OPER)
{ ptr->rgt = ptr->rgt->rgt;
break;
}
/* NEW : G X p == X G p */
if (ptr->lft->ntyp == FALSE &&
ptr->rgt->ntyp == NEXT) {
ptr = tl_nn(NEXT, tl_nn(V_OPER, False, ptr->rgt->lft, miscell), ZN, miscell);
break;
}
/* NEW : G F G p == F G p */
if (ptr->lft->ntyp == FALSE &&
ptr->rgt->ntyp == U_OPER &&
ptr->rgt->lft->ntyp == TRUE &&
ptr->rgt->rgt->ntyp == V_OPER &&
ptr->rgt->rgt->lft->ntyp == FALSE) {
ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->rgt->ntyp == V_OPER
&& implies(ptr->rgt->lft, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->rgt;
break;
}
/* NEW */
if (ptr->lft->ntyp != FALSE &&
implies(ptr->lft,
push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN, miscell), miscell, cnt, uform, tl_yychar), cnt, uform, tl_yychar, miscell))
{ ptr->lft = False;
break;
}
break;
case NEXT:
/* NEW : X G F p == G F p */
if (ptr->lft->ntyp == V_OPER &&
ptr->lft->lft->ntyp == FALSE &&
ptr->lft->rgt->ntyp == U_OPER &&
ptr->lft->rgt->lft->ntyp == TRUE) {
break;
}
/* NEW : X F G p == F G p */
if (ptr->lft->ntyp == U_OPER &&
ptr->lft->lft->ntyp == TRUE &&
ptr->lft->rgt->ntyp == V_OPER &&
ptr->lft->rgt->lft->ntyp == FALSE) {
break;
}
break;
case ALWAYS:
/* NEW : [] G F p == G F p */
if (ptr->rgt->ntyp == V_OPER &&
ptr->rgt->rgt->ntyp == FALSE &&
ptr->rgt->lft->ntyp == U_OPER &&
ptr->rgt->lft->rgt->ntyp == TRUE) {
ptr = ptr->rgt;
break;
}
/* NEW : [] F G p == F G p */
if (ptr->rgt->ntyp == U_OPER &&
ptr->rgt->rgt->ntyp == TRUE &&
ptr->rgt->lft->ntyp == V_OPER &&
ptr->rgt->lft->rgt->ntyp == FALSE) {
ptr = ptr->rgt;
break;
}
break;
case IMPLIES:
if (implies(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = True;
break;
}
ptr = tl_nn(OR, Not(ptr->lft), ptr->rgt, miscell);
ptr = canonical(right_linked(ptr), miscell, cnt, uform, tl_yychar);
break;
case EQUIV:
if (implies(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell) &&
implies(ptr->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = True;
break;
}
a = canonical(right_linked(tl_nn(AND,
dupnode(ptr->lft),
dupnode(ptr->rgt), miscell)), miscell, cnt, uform, tl_yychar);
b = canonical(right_linked(tl_nn(AND,
Not(ptr->lft),
Not(ptr->rgt), miscell)), miscell, cnt, uform, tl_yychar);
ptr = tl_nn(OR, a, b, miscell);
ptr = canonical(right_linked(ptr), miscell, cnt, uform, tl_yychar);
break;
case AND:
/* p && (q U p) = p */
if (ptr->rgt->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->lft;
break;
}
if (ptr->lft->ntyp == U_OPER
&& isequal(ptr->lft->rgt, ptr->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->rgt;
break;
}
/* p && (q V p) == q V p */
if (ptr->rgt->ntyp == V_OPER
&& isequal(ptr->rgt->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->rgt;
break;
}
if (ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->lft;
break;
}
/* (p U q) && (r U q) = (p && r) U q*/
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = tl_nn(U_OPER,
tl_nn(AND, ptr->lft->lft, ptr->rgt->lft, miscell),
ptr->lft->rgt, miscell);
break;
}
/* (p V q) && (p V r) = p V (q && r) */
if (ptr->rgt->ntyp == V_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->rgt->lft, ptr->lft->lft, cnt, uform, tl_yychar, miscell))
{ ptr = tl_nn(V_OPER,
ptr->rgt->lft,
tl_nn(AND, ptr->lft->rgt, ptr->rgt->rgt, miscell), miscell);
break;
}
/* X p && X q == X (p && q) */
if (ptr->rgt->ntyp == NEXT
&& ptr->lft->ntyp == NEXT)
{ ptr = tl_nn(NEXT,
tl_nn(AND,
ptr->rgt->lft,
ptr->lft->lft, miscell), ZN, miscell);
break;
}
/* (p V q) && (r U q) == p V q */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->lft;
break;
}
if (isequal(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell) /* (p && p) == p */
|| ptr->rgt->ntyp == FALSE /* (p && F) == F */
|| ptr->lft->ntyp == TRUE /* (T && p) == p */
|| implies(ptr->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))/* NEW */
{ ptr = ptr->rgt;
break;
}
if (ptr->rgt->ntyp == TRUE /* (p && T) == p */
|| ptr->lft->ntyp == FALSE /* (F && p) == F */
|| implies(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell))/* NEW */
{ ptr = ptr->lft;
break;
}
/* NEW : F G p && F G q == F G (p && q) */
if (ptr->lft->ntyp == U_OPER &&
ptr->lft->lft->ntyp == TRUE &&
ptr->lft->rgt->ntyp == V_OPER &&
ptr->lft->rgt->lft->ntyp == FALSE &&
ptr->rgt->ntyp == U_OPER &&
ptr->rgt->lft->ntyp == TRUE &&
ptr->rgt->rgt->ntyp == V_OPER &&
ptr->rgt->rgt->lft->ntyp == FALSE)
{
ptr = tl_nn(U_OPER, True,
tl_nn(V_OPER, False,
tl_nn(AND, ptr->lft->rgt->rgt,
ptr->rgt->rgt->rgt, miscell), miscell), miscell);
break;
}
/* NEW */
if (implies(ptr->lft,
push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN, miscell), miscell, cnt, uform, tl_yychar), cnt, uform, tl_yychar, miscell)
|| implies(ptr->rgt,
push_negation(tl_nn(NOT, dupnode(ptr->lft), ZN, miscell), miscell, cnt, uform, tl_yychar), cnt, uform, tl_yychar, miscell))
{ ptr = False;
break;
}
break;
case OR:
/* p || (q U p) == q U p */
if (ptr->rgt->ntyp == U_OPER
&& isequal(ptr->rgt->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->rgt;
break;
}
/* p || (q V p) == p */
if (ptr->rgt->ntyp == V_OPER
&& isequal(ptr->rgt->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->lft;
break;
}
/* (p U q) || (p U r) = p U (q || r) */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == U_OPER
&& isequal(ptr->rgt->lft, ptr->lft->lft, cnt, uform, tl_yychar, miscell))
{ ptr = tl_nn(U_OPER,
ptr->rgt->lft,
tl_nn(OR, ptr->lft->rgt, ptr->rgt->rgt, miscell), miscell);
break;
}
if (isequal(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell) /* (p || p) == p */
|| ptr->rgt->ntyp == FALSE /* (p || F) == p */
|| ptr->lft->ntyp == TRUE /* (T || p) == T */
|| implies(ptr->rgt, ptr->lft, cnt, uform, tl_yychar, miscell))/* NEW */
{ ptr = ptr->lft;
break;
}
if (ptr->rgt->ntyp == TRUE /* (p || T) == T */
|| ptr->lft->ntyp == FALSE /* (F || p) == p */
|| implies(ptr->lft, ptr->rgt, cnt, uform, tl_yychar, miscell))/* NEW */
{ ptr = ptr->rgt;
break;
}
/* (p V q) || (r V q) = (p || r) V q */
if (ptr->rgt->ntyp == V_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = tl_nn(V_OPER,
tl_nn(OR, ptr->lft->lft, ptr->rgt->lft, miscell),
ptr->rgt->rgt, miscell);
break;
}
/* (p V q) || (r U q) == r U q */
if (ptr->rgt->ntyp == U_OPER
&& ptr->lft->ntyp == V_OPER
&& isequal(ptr->lft->rgt, ptr->rgt->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = ptr->rgt;
break;
}
/* NEW : G F p || G F q == G F (p || q) */
if (ptr->lft->ntyp == V_OPER &&
ptr->lft->lft->ntyp == FALSE &&
ptr->lft->rgt->ntyp == U_OPER &&
ptr->lft->rgt->lft->ntyp == TRUE &&
ptr->rgt->ntyp == V_OPER &&
ptr->rgt->lft->ntyp == FALSE &&
ptr->rgt->rgt->ntyp == U_OPER &&
ptr->rgt->rgt->lft->ntyp == TRUE)
{
ptr = tl_nn(V_OPER, False,
tl_nn(U_OPER, True,
tl_nn(OR, ptr->lft->rgt->rgt,
ptr->rgt->rgt->rgt, miscell), miscell), miscell);
break;
}
/* NEW */
if (implies(push_negation(tl_nn(NOT, dupnode(ptr->rgt), ZN, miscell), miscell, cnt, uform, tl_yychar),
ptr->lft, cnt, uform, tl_yychar, miscell)
|| implies(push_negation(tl_nn(NOT, dupnode(ptr->lft), ZN, miscell), miscell, cnt, uform, tl_yychar),
ptr->rgt, cnt, uform, tl_yychar, miscell))
{ ptr = True;
break;
}
break;
}
return ptr;
}
static Node *tl_factor(int *cnt, size_t hasuform, char *uform, Miscellaneous *miscell, int *tl_yychar)
{
Node *ptr = ZN;
int tl_simp_log_p = 0;
switch ((*tl_yychar))
{
case '(':
ptr = tl_formula(cnt, hasuform, uform, miscell, tl_yychar);
if ((*tl_yychar) != ')')
tl_yyerror("expected ')'", cnt, uform, tl_yychar, miscell);
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
goto simpl;
case NOT:
ptr = miscell->tl_yylval;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
ptr->lft = tl_factor(cnt, hasuform, uform, miscell, tl_yychar);
ptr = push_negation(ptr, miscell, cnt, uform, tl_yychar);
goto simpl;
case ALWAYS:
ptr = tl_nn(ALWAYS, False, ZN, miscell);
ptr->time = miscell->TimeCon;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
ptr->rgt = tl_factor(cnt, hasuform, uform, miscell, tl_yychar);
goto simpl;
case NEXT:
ptr = tl_nn(NEXT, ZN, ZN, miscell);
ptr->time = miscell->TimeCon;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
ptr->lft = tl_factor(cnt, hasuform, uform, miscell, tl_yychar);
goto simpl;
case WEAKNEXT:
ptr = tl_nn(WEAKNEXT, ZN, ZN, miscell);
ptr->time = miscell->TimeCon;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
ptr->lft = tl_factor(cnt, hasuform, uform, miscell, tl_yychar);
goto simpl;
case EVENTUALLY:
ptr = tl_nn(EVENTUALLY, True, ZN, miscell);
ptr->time = miscell->TimeCon;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
ptr->rgt = tl_factor(cnt, hasuform, uform, miscell, tl_yychar);
goto simpl;
/* case IMPLIES:
ptr = tl_nn(OR, Not(ptr->lft), ptr->rgt);
goto simpl;
/* case EQUIV:
a = tl_nn(AND,dupnode(ptr->lft),dupnode(ptr->rgt));
b = tl_nn(AND,Not(ptr->lft),Not(ptr->rgt));
ptr = tl_nn(OR, a, b); */
simpl:
if (tl_simp_log_p)
ptr = bin_simpler(ptr,miscell,cnt,uform, tl_yychar);
break;
case PREDICATE:
ptr = miscell->tl_yylval;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
break;
case TRUE:
case FALSE:
ptr = miscell->tl_yylval;
(*tl_yychar) = tl_yylex(cnt, hasuform, uform, miscell, tl_yychar);
break;
}
if (!ptr) tl_yyerror("expected predicate", cnt, uform, tl_yychar, miscell);
#if 0
printf("factor: ");
tl_explain(ptr->ntyp);
printf("\n");
#endif
return ptr;
}