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working on pb pre-processing/subsumption

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-12-26 10:14:05 -08:00
parent 0641c4f694
commit a0e98ca39b
1 changed files with 47 additions and 4 deletions
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51
src/tactic/core/pb_preprocess_tactic.cpp
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@ -150,11 +150,10 @@ public:
proof_converter_ref & pc,
expr_dependency_ref & core) {
SASSERT(g->is_well_sorted());
mc = 0; pc = 0; core = 0;
pc = 0; core = 0;
// TBD: bail out if cores are enabled.
// TBD: bail out if proofs are enabled/add proofs.
// TBD: model construction by back-filling solutions.
pb_preproc_model_converter* pp = alloc(pb_preproc_model_converter, m);
mc = pp;
@ -162,7 +161,6 @@ public:
g->inc_depth();
result.push_back(g.get());
while (simplify(g, *pp));
}
bool simplify(goal_ref const& g, pb_preproc_model_converter& mc) {
@ -228,7 +226,34 @@ public:
++it;
it = next_resolvent(it);
}
// now check for subsumption.
for (unsigned i = 0; i < m_ge.size(); ++i) {
expr_ref_vector args1(m), args2(m);
vector<rational> coeffs1, coeffs2;
rational k1, k2;
expr* fml = g->form(m_ge[i]);
if (!to_ge(fml, args1, coeffs1, k1)) continue;
if (args1.empty()) continue;
expr* arg = args1[0].get();
bool neg = m.is_not(arg, arg);
if (!is_uninterp_const(arg)) continue;
rec const& r = m_vars.find(to_app(arg));
unsigned_vector const& pos = neg?r.neg:r.pos;
for (unsigned j = 0; j < pos.size(); ++j) {
unsigned k = pos[j];
if (k == i) continue;
if (!to_ge(g->form(k), args2, coeffs2, k2)) continue;
if (subsumes(args1, coeffs1, k1, args2, coeffs2, k2)) {
g->update(k, m.mk_true());
m_progress = true;
}
}
}
g->elim_true();
return m_progress;
}
@ -487,7 +512,7 @@ private:
}
else if (m.is_or(e)) {
app* a = to_app(e);
SASSERT(pure_args(e));
SASSERT(pure_args(a));
for (unsigned i = 0; i < a->get_num_args(); ++i) {
args.push_back(a->get_arg(i));
coeffs.push_back(rational::one());
@ -519,6 +544,24 @@ private:
}
m_r.set_substitution(0);
}
bool subsumes(expr_ref_vector const& args1,
vector<rational> const& coeffs1, rational const& k1,
expr_ref_vector const& args2,
vector<rational> const& coeffs2, rational const& k2) {
if (k2 > k1) return false;
for (unsigned i = 0; i < args1.size(); ++i) {
bool found = false;
for (unsigned j = 0; !found && j < args2.size(); ++j) {
if (args1[i] == args2[j]) {
if (coeffs1[1] > coeffs2[j]) return false;
found = true;
}
}
if (!found) return false;
}
return true;
}
};