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convert assign-bounds axioms to farkas lemmas

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This commit is contained in:
Arie Gurfinkel 2018-06-20 23:07:01 -04:00
parent ac23002dce
commit 9c9d0d0840
1 changed files with 65 additions and 9 deletions
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74
src/muz/spacer/spacer_proof_utils.cpp
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@ -45,7 +45,7 @@ namespace spacer {
return false;
}
// farkas lemma recognizer
// farkas lemma recognizer
bool is_farkas_lemma(ast_manager& m, proof* pr)
{
if (pr->get_decl_kind() == PR_TH_LEMMA)
@ -59,6 +59,19 @@ namespace spacer {
return false;
}
static bool is_assign_bounds_lemma(ast_manager &m, proof *pr) {
if (pr->get_decl_kind() == PR_TH_LEMMA)
{
func_decl* d = pr->get_decl();
symbol sym;
return d->get_num_parameters() >= 2 &&
d->get_parameter(0).is_symbol(sym) && sym == "arith" &&
d->get_parameter(1).is_symbol(sym) && sym == "assign-bounds";
}
return false;
}
/*
* ====================================
@ -71,8 +84,8 @@ namespace spacer {
m_pinned.reset();
}
static proof* mk_th_lemma(ast_manager &m, ptr_buffer<proof> const &parents,
unsigned num_params, parameter const *params) {
static proof_ref mk_th_lemma(ast_manager &m, ptr_buffer<proof> const &parents,
unsigned num_params, parameter const *params) {
buffer<parameter> v;
for (unsigned i = 1; i < num_params; ++i)
v.push_back(params[i]);
@ -81,12 +94,45 @@ namespace spacer {
family_id tid = m.mk_family_id(params[0].get_symbol());
SASSERT(tid != null_family_id);
return m.mk_th_lemma(tid, m.mk_false(),
parents.size(), parents.c_ptr(),
num_params-1, v.c_ptr());
proof *pf = m.mk_th_lemma(tid, m.mk_false(),
parents.size(), parents.c_ptr(),
v.size(), v.c_ptr());
return proof_ref(pf, m);
}
// -- rewrite theory axioms into theory lemmas
// convert assign-bounds lemma to a farkas lemma by adding missing coeff
// assume that missing coeff is for premise at position 0
static proof_ref mk_fk_from_ab(ast_manager &m,
ptr_buffer<proof> const &parents,
unsigned num_params,
parameter const *params) {
SASSERT(num_params == parents.size() + 1 /* one param is missing */);
buffer<parameter> v;
v.push_back(parameter(symbol("farkas")));
v.push_back(parameter(rational(1)));
for (unsigned i = 2; i < num_params; ++i)
v.push_back(params[i]);
SASSERT(params[0].is_symbol());
family_id tid = m.mk_family_id(params[0].get_symbol());
SASSERT(tid != null_family_id);
proof_ref pf(m);
pf = m.mk_th_lemma(tid, m.mk_false(),
parents.size(), parents.c_ptr(),
v.size(), v.c_ptr());
SASSERT(is_arith_lemma(m, pf));
DEBUG_CODE(
proof_checker pc(m);
expr_ref_vector side(m);
SASSERT(pc.check(pf, side));
);
return pf;
}
/// -- rewrite theory axioms into theory lemmas
proof_ref theory_axiom_reducer::reduce(proof* pr) {
proof_post_order pit(pr, m);
while (pit.hasNext()) {
@ -124,9 +170,19 @@ namespace spacer {
}
// (b) Create a theory lemma
proof *th_lemma;
proof_ref th_lemma(m);
func_decl *d = p->get_decl();
th_lemma = mk_th_lemma(m, hyps, d->get_num_parameters(), d->get_parameters());
if (is_assign_bounds_lemma(m, p)) {
th_lemma = mk_fk_from_ab(m, hyps,
d->get_num_parameters(),
d->get_parameters());
}
else {
th_lemma = mk_th_lemma(m, hyps,
d->get_num_parameters(),
d->get_parameters());
}
m_pinned.push_back(th_lemma);
SASSERT(is_arith_lemma(m, th_lemma));