int
main (void)
{
Btor *btor;
BtorNode *array, *read, *max, *temp, *ugt, *formula, *index;
BtorNode *indices[ARRAY1_EXAMPLE_ARRAY_SIZE];
int i, result;
btor = boolector_new ();
/* We create all possible constants that are used as read indices */
for (i = 0; i < ARRAY1_EXAMPLE_ARRAY_SIZE; i++)
indices[i] = boolector_int (btor, i, ARRAY1_EXAMPLE_INDEX_BW);
array =
boolector_array (btor, ARRAY1_EXAMPLE_VALUE_BW, ARRAY1_EXAMPLE_INDEX_BW,
NULL);
/* Current maximum is first element of array */
max = boolector_read (btor, array, indices[0]);
/* Symbolic loop unrolling */
for (i = 1; i < ARRAY1_EXAMPLE_ARRAY_SIZE; i++)
{
read = boolector_read (btor, array, indices[i]);
ugt = boolector_ugt (btor, read, max);
/* found a new maximum? */
temp = boolector_cond (btor, ugt, read, max);
boolector_release (btor, max);
max = temp;
boolector_release (btor, read);
boolector_release (btor, ugt);
}
/* Now we show that 'max' is indeed a maximum */
/* We read at an arbitrary position */
index = boolector_var (btor, ARRAY1_EXAMPLE_INDEX_BW, NULL);
read = boolector_read (btor, array, index);
/* We assume that it is possible that the read value is greater than 'max' */
formula = boolector_ugt (btor, read, max);
/* We assert the formula and call Boolector */
boolector_assert (btor, formula);
result = boolector_sat (btor);
if (result == BOOLECTOR_UNSAT)
printf ("Formula is unsatisfiable\n");
else
abort ();
/* clean up */
for (i = 0; i < ARRAY1_EXAMPLE_ARRAY_SIZE; i++)
boolector_release (btor, indices[i]);
boolector_release (btor, formula);
boolector_release (btor, read);
boolector_release (btor, index);
boolector_release (btor, max);
boolector_release (btor, array);
assert (boolector_get_refs (btor) == 0);
boolector_delete (btor);
return 0;
}
int
main ()
{
int sat_result;
BtorExp *array, *index1, *index2, *read1, *read2, *eq, *ne;
Btor *btor;
btor = boolector_new ();
boolector_enable_inc_usage (btor);
array =
boolector_array (btor, ARRAY3_EXAMPLE_VALUE_BW, ARRAY3_EXAMPLE_INDEX_BW,
NULL);
index1 = boolector_var (btor, ARRAY3_EXAMPLE_INDEX_BW, NULL);
index2 = boolector_var (btor, ARRAY3_EXAMPLE_INDEX_BW, NULL);
read1 = boolector_read (btor, array, index1);
read2 = boolector_read (btor, array, index2);
eq = boolector_eq (btor, index1, index2);
ne = boolector_ne (btor, read1, read2);
/* we enforce that index1 is equal to index 2 */
boolector_assert (btor, eq);
sat_result = boolector_sat (btor);
assert (sat_result == BOOLECTOR_SAT);
/* now we additionally assume that the read values differ
* the instance is now unsatasfiable as read congruence is violated */
boolector_assume (btor, ne);
sat_result = boolector_sat (btor);
assert (sat_result == BOOLECTOR_UNSAT);
/* after the SAT call the assumptions are gone
* the instance is now satisfiable again */
sat_result = boolector_sat (btor);
assert (sat_result == BOOLECTOR_SAT);
boolector_release (btor, array);
boolector_release (btor, index1);
boolector_release (btor, index2);
boolector_release (btor, read1);
boolector_release (btor, read2);
boolector_release (btor, eq);
boolector_release (btor, ne);
boolector_delete (btor);
return 0;
}
