static bool
primes_consensus_special_cases(pset *T, pset_family *Tnew)
/* will be disposed if answer is determined */
/* returned only if answer determined */
{
register pcube *T1, p, ceil, cof=T[0];
pcube last;
pcover A;
/* Check for no cubes in the cover */
if (T[2] == NULL) {
*Tnew = new_cover(0);
free_cubelist(T);
return TRUE;
}
/* Check for only a single cube in the cover */
if (T[3] == NULL) {
*Tnew = sf_addset(new_cover(1), set_or(cof, cof, T[2]));
free_cubelist(T);
return TRUE;
}
/* Check for a row of all 1's (implies function is a tautology) */
for(T1 = T+2; (p = *T1++) != NULL; ) {
if (full_row(p, cof)) {
*Tnew = sf_addset(new_cover(1), cube.fullset);
free_cubelist(T);
return TRUE;
}
}
/* Check for a column of all 0's which can be factored out */
ceil = set_save(cof);
for(T1 = T+2; (p = *T1++) != NULL; ) {
INLINEset_or(ceil, ceil, p);
}
if (! setp_equal(ceil, cube.fullset)) {
p = new_cube();
(void) set_diff(p, cube.fullset, ceil);
(void) set_or(cof, cof, p);
free_cube(p);
A = primes_consensus(T);
foreach_set(A, last, p) {
INLINEset_and(p, p, ceil);
}
static bool compl_special_cases(pset *T, pset_family *Tbar)
/* will be disposed if answer is determined */
/* returned only if answer determined */
{
register pcube *T1, p, ceil, cof=T[0];
pcover A, ceil_compl;
/* Check for no cubes in the cover */
if (T[2] == NULL) {
*Tbar = sf_addset(new_cover(1), cube.fullset);
free_cubelist(T);
return TRUE;
}
/* Check for only a single cube in the cover */
if (T[3] == NULL) {
*Tbar = compl_cube(set_or(cof, cof, T[2]));
free_cubelist(T);
return TRUE;
}
/* Check for a row of all 1's (implies complement is null) */
for(T1 = T+2; (p = *T1++) != NULL; ) {
if (full_row(p, cof)) {
*Tbar = new_cover(0);
free_cubelist(T);
return TRUE;
}
}
/* Check for a column of all 0's which can be factored out */
ceil = set_save(cof);
for(T1 = T+2; (p = *T1++) != NULL; ) {
INLINEset_or(ceil, ceil, p);
}
if (! setp_equal(ceil, cube.fullset)) {
ceil_compl = compl_cube(ceil);
(void) set_or(cof, cof, set_diff(ceil, cube.fullset, ceil));
set_free(ceil);
*Tbar = sf_append(complement(T), ceil_compl);
return TRUE;
}
set_free(ceil);
/* Collect column counts, determine unate variables, etc. */
massive_count(T);
/* If single active variable not factored out above, then tautology ! */
if (cdata.vars_active == 1) {
*Tbar = new_cover(0);
free_cubelist(T);
return TRUE;
/* Check for unate cover */
} else if (cdata.vars_unate == cdata.vars_active) {
A = map_cover_to_unate(T);
free_cubelist(T);
A = unate_compl(A);
*Tbar = map_unate_to_cover(A);
sf_free(A);
return TRUE;
/* Not much we can do about it */
} else {
return MAYBE;
}
}
static bool
compl_special_cases(set **T, set_family_t **Tbar)
{
set **T1, *p, *ceil, *cof=T[0];
set_family_t *A, *ceil_compl;
// Check for no cubes in the cover
if (T[2] == NULL) {
*Tbar = sf_addset(sf_new(1, CUBE.size), CUBE.fullset);
free_cubelist(T);
return TRUE;
}
// Check for only a single cube in the cover
if (T[3] == NULL) {
*Tbar = compl_cube(set_or(cof, cof, T[2]));
free_cubelist(T);
return TRUE;
}
// Check for a row of all 1's (implies complement is null)
for (T1 = T+2; (p = *T1++) != NULL; ) {
if (full_row(p, cof)) {
*Tbar = sf_new(0, CUBE.size);
free_cubelist(T);
return TRUE;
}
}
// Check for a column of all 0's which can be factored out
ceil = set_save(cof);
for (T1 = T+2; (p = *T1++) != NULL; ) {
set_or(ceil, ceil, p);
}
if (! setp_equal(ceil, CUBE.fullset)) {
ceil_compl = compl_cube(ceil);
set_or(cof, cof, set_diff(ceil, CUBE.fullset, ceil));
set_free(ceil);
*Tbar = sf_append(complement(T), ceil_compl);
return TRUE;
}
set_free(ceil);
// Collect column counts, determine unate variables, etc.
massive_count(T);
// If single active variable not factored out above, then tautology!
if (CDATA.vars_active == 1) {
*Tbar = sf_new(0, CUBE.size);
free_cubelist(T);
return TRUE;
// Check for unate cover
} else if (CDATA.vars_unate == CDATA.vars_active) {
A = map_cover_to_unate(T);
free_cubelist(T);
A = unate_compl(A);
*Tbar = map_unate_to_cover(A);
sf_free(A);
return TRUE;
// Not much we can do about it
} else {
return MAYBE;
}
}
