int
main (void)
{
Btor *btor;
BtorNode *x, *y, *temp, *old_x, *old_y, *eq1, *eq2, *and, *formula;
int result;
btor = boolector_new ();
x = boolector_var (btor, BV1_EXAMPLE_NUM_BITS, NULL);
y = boolector_var (btor, BV1_EXAMPLE_NUM_BITS, NULL);
/* remember initial values of x and y */
old_x = boolector_copy (btor, x);
old_y = boolector_copy (btor, y);
/* x = x ^ y */
temp = boolector_xor (btor, x, y);
boolector_release (btor, x);
x = temp;
/* y = x ^ y */
temp = boolector_xor (btor, x, y);
boolector_release (btor, y);
y = temp;
/* x = x ^ y */
temp = boolector_xor (btor, x, y);
boolector_release (btor, x);
x = temp;
/* Now, we have to show that old_x = y and old_y = x */
eq1 = boolector_eq (btor, old_x, y);
eq2 = boolector_eq (btor, old_y, x);
and = boolector_and (btor, eq1, eq2);
/* In order to prove that this is a theorem, we negate the whole
* formula and show that the negation is unsatisfiable */
formula = boolector_not (btor, and);
/* 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 ();
/* cleanup */
boolector_release (btor, x);
boolector_release (btor, old_x);
boolector_release (btor, y);
boolector_release (btor, old_y);
boolector_release (btor, eq1);
boolector_release (btor, eq2);
boolector_release (btor, and);
boolector_release (btor, formula);
assert (boolector_get_refs (btor) == 0);
boolector_delete (btor);
return 0;
}
literalt boolector_propt::lxor(const bvt &bv)
{
if(bv.size()==0) return const_literal(false);
if(bv.size()==1) return bv[0];
literalt l=new_variable();
u_int size=bv.size()+1;
BtorExp *args[size], *result;
for(unsigned int i=0; i<bv.size(); i++)
{
args[i] = boolector_literal(bv[i]);
if (i==1)
result = boolector_xor(boolector_ctx, args[0], args[1]);
else if (i>1)
result = boolector_xor(boolector_ctx, result, args[i]);
}
boolector_assert(boolector_ctx, boolector_iff(boolector_ctx, boolector_literal(l), result));
return l;
}
void
V3SvrBoolector::add_XOR_Formula(const V3NetId& out, const uint32_t& depth) {
// Check Output Validation
assert (validNetId(out)); assert (BV_XOR == _ntk->getGateType(out)); assert (!getVerifyData(out, depth));
const uint32_t index = getV3NetIndex(out); assert (depth == _ntkData[index].size());
// Build XOR I/O Relation
const V3NetId in1 = _ntk->getInputNetId(out, 0); assert (validNetId(in1));
const V3NetId in2 = _ntk->getInputNetId(out, 1); assert (validNetId(in2));
BtorExp* const exp1 = getVerifyData(in1, depth); assert (exp1);
BtorExp* const exp2 = getVerifyData(in2, depth); assert (exp2);
// Set BtorExp*
_ntkData[index].push_back(boolector_xor(_Solver, exp1, exp2));
assert (getVerifyData(out, depth));
}
literalt boolector_propt::lxor(literalt a, literalt b)
{
if(a==const_literal(false)) return b;
if(b==const_literal(false)) return a;
if(a==const_literal(true)) return lnot(b);
if(b==const_literal(true)) return lnot(a);
literalt l=new_variable();
BtorExp *result;
result = boolector_xor(boolector_ctx, boolector_literal(a), boolector_literal(b));
boolector_assert(boolector_ctx, boolector_iff(boolector_ctx, boolector_literal(l), result));
return l;
}