Facts *new_Facts( void )
{
Facts *result = ( Facts * ) calloc( 1, sizeof( Facts ) );
CHECK_PTR(result);
result->fact = new_Fact();
result->next = NULL;
return result;
}
WffNode *instantiate_wff( WffNode *w )
{
WffNode *res = NULL, *tmp, *i;
int j, c0, c1, m, h;
Bool ok;
switch ( w->connective ) {
case AND:
m = 0;
i = w->sons;
while ( i ) {
tmp = instantiate_wff( i );
if ( tmp->connective == FAL ) {
free_WffNode( res );
return tmp;
}
if ( tmp->connective == TRU ) {
free( tmp );
i = i->next;
continue;
}
tmp->next = res;
if ( res ) {
res->prev = tmp;
}
res = tmp;
i = i->next;
m++;
}
if ( m == 0 ) {
res = new_WffNode( TRU );
break;
}
if ( m == 1 ) {
break;
}
tmp = new_WffNode( AND );
tmp->sons = res;
res = tmp;
break;
case OR:
m = 0;
i = w->sons;
while ( i ) {
tmp = instantiate_wff( i );
if ( tmp->connective == TRU ) {
free_WffNode( res );
return tmp;
}
if ( tmp->connective == FAL ) {
free( tmp );
i = i->next;
continue;
}
tmp->next = res;
if ( res ) {
res->prev = tmp;
}
res = tmp;
i = i->next;
m++;
}
if ( m == 0 ) {
res = new_WffNode( FAL );
break;
}
if ( m == 1 ) {
break;
}
tmp = new_WffNode( OR );
tmp->sons = res;
res = tmp;
break;
case NOT:
/* must be non-equality
*/
c0 = ( w->son->fact->args[0] < 0 ) ?
linst_table[DECODE_VAR( w->son->fact->args[0] )] : w->son->fact->args[0];
c1 = ( w->son->fact->args[1] < 0 ) ?
linst_table[DECODE_VAR( w->son->fact->args[1] )] : w->son->fact->args[1];
if ( c0 < 0 ||
c1 < 0 ) {
/* ef param while checking ef conds in inst op
*/
res = new_WffNode( ATOM );
res->fact = new_Fact();
res->fact->predicate = -2;
res->fact->args[0] = ( c0 < 0 ) ? w->son->fact->args[0] : c0;
res->fact->args[1] = ( c1 < 0 ) ? w->son->fact->args[1] : c1;
break;
}
if ( c0 != c1 ) {
res = new_WffNode( TRU );
} else {
res = new_WffNode( FAL );
}
break;
case ATOM:
res = new_WffNode( ATOM );
res->fact = new_Fact();
res->fact->predicate = w->fact->predicate;
ok = TRUE;
for ( j = 0; j < garity[res->fact->predicate]; j++ ) {
h = ( w->fact->args[j] < 0 ) ?
linst_table[DECODE_VAR( w->fact->args[j] )] : w->fact->args[j];
if ( h < 0 ) {
ok = FALSE;
res->fact->args[j] = w->fact->args[j];
} else {
res->fact->args[j] = h;
}
}
if ( !ok ) {/* contains ef params */
break;
}
if ( !full_possibly_negative( res->fact ) ) {
free( res->fact );
res->fact = NULL;
res->connective = TRU;
break;
}
if ( !full_possibly_positive( res->fact ) ) {
free( res->fact );
res->fact = NULL;
res->connective = FAL;
break;
}
break;
case TRU:
case FAL:
res = new_WffNode( w->connective );
break;
default:
printf("\n\nillegal connective %d in instantiate formula\n\n",
w->connective);
exit( 1 );
}
return res;
}
WffNode *instantiate_wff( WffNode *w )
{
WffNode *res = NULL, *tmp, *i;
int j, m, h;
Bool ok, ct;
switch ( w->connective ) {
case AND:
m = 0;
i = w->sons;
while ( i ) {
tmp = instantiate_wff( i );
if ( tmp->connective == FAL ) {
free_WffNode( res );
return tmp;
}
if ( tmp->connective == TRU ) {
free( tmp );
i = i->next;
continue;
}
tmp->next = res;
if ( res ) {
res->prev = tmp;
}
res = tmp;
i = i->next;
m++;
}
if ( m == 0 ) {
res = new_WffNode( TRU );
break;
}
if ( m == 1 ) {
break;
}
tmp = new_WffNode( AND );
tmp->sons = res;
res = tmp;
break;
case OR:
m = 0;
i = w->sons;
while ( i ) {
tmp = instantiate_wff( i );
if ( tmp->connective == TRU ) {
free_WffNode( res );
return tmp;
}
if ( tmp->connective == FAL ) {
free( tmp );
i = i->next;
continue;
}
tmp->next = res;
if ( res ) {
res->prev = tmp;
}
res = tmp;
i = i->next;
m++;
}
if ( m == 0 ) {
res = new_WffNode( FAL );
break;
}
if ( m == 1 ) {
break;
}
tmp = new_WffNode( OR );
tmp->sons = res;
res = tmp;
break;
case ATOM:
res = new_WffNode( ATOM );
res->fact = new_Fact();
res->fact->predicate = w->fact->predicate;
ok = TRUE;
for ( j = 0; j < garity[res->fact->predicate]; j++ ) {
h = ( w->fact->args[j] < 0 ) ?
linst_table[DECODE_VAR( w->fact->args[j] )] : w->fact->args[j];
if ( h < 0 ) {
ok = FALSE;
res->fact->args[j] = w->fact->args[j];
} else {
res->fact->args[j] = h;
}
}
if ( !ok ) {/* contains ef params */
break;
}
if ( !full_possibly_negative( res->fact ) ) {
free( res->fact );
res->fact = NULL;
res->connective = TRU;
break;
}
if ( !full_possibly_positive( res->fact ) ) {
free( res->fact );
res->fact = NULL;
res->connective = FAL;
break;
}
break;
case COMP:
res = new_WffNode( COMP );
res->comp = w->comp;
res->lh = copy_Exp( w->lh );
res->rh = copy_Exp( w->rh );
instantiate_exp( &(res->lh) );
instantiate_exp( &(res->rh) );
if ( res->lh->connective != NUMBER ||
res->rh->connective != NUMBER ) {
/* logical simplification only possible if both parts are numbers
*/
break;
}
ct = number_comparison_holds( res->comp, res->lh->value, res->rh->value );
if ( ct ) {
res->connective = TRU;
free_ExpNode( res->lh );
res->lh = NULL;
free_ExpNode( res->rh );
res->rh = NULL;
res->comp = -1;
} else {
res->connective = FAL;
free_ExpNode( res->lh );
res->lh = NULL;
free_ExpNode( res->rh );
res->rh = NULL;
res->comp = -1;
}
break;
case TRU:
case FAL:
res = new_WffNode( w->connective );
break;
default:
printf("\n\nillegal connective %d in instantiate formula\n\n",
w->connective);
exit( 1 );
}
return res;
}
