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more refinements for recfun

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-10-17 10:02:56 -07:00
parent 48cdd12a47
commit 8a9837a8b5
3 changed files with 38 additions and 36 deletions
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2
src/smt/smt_theory.h
View file

@ -294,6 +294,8 @@ namespace smt {
SASSERT(m_context);
return *m_context;
}
context & ctx() const { return get_context(); }
ast_manager & get_manager() const {
SASSERT(m_manager);

70
src/smt/theory_recfun.cpp
View file

@ -52,7 +52,7 @@ namespace smt {
void theory_recfun::setup_params() {
// obtain max depth via parameters
smt_params_helper p(get_context().get_params());
smt_params_helper p(ctx().get_params());
set_max_depth(p.recfun_max_depth());
}
@ -175,13 +175,11 @@ namespace smt {
{
// first literal must be the depth limit one
app_ref dlimit = m_util.mk_depth_limit_pred(get_max_depth());
ctx.internalize(dlimit, false);
c.push_back(~ ctx.get_literal(dlimit));
SASSERT(ctx.get_assignment(ctx.get_literal(dlimit)) == l_true);
c.push_back(~mk_literal(dlimit));
SASSERT(ctx.get_assignment(c.back()) == l_true);
}
for (auto& kv : m_guards) {
expr * g = & kv.get_key();
c.push_back(~ ctx.get_literal(g));
c.push_back(~ mk_literal(&kv.get_key()));
}
TRACEFN("max-depth limit: add clause " << pp_lits(ctx, c));
SASSERT(std::all_of(c.begin(), c.end(), [&](literal & l) { return ctx.get_assignment(l) == l_false; })); // conflict
@ -197,12 +195,12 @@ namespace smt {
if (u().is_case_pred(a)) {
TRACEFN("assign_case_pred_true "<< mk_pp(e,m()));
// add to set of local assumptions, for depth-limit purpose
{
m_guards.insert(e, empty());
m().inc_ref(e);
insert_ref_map<theory_recfun,guard_set,ast_manager,expr*> trail_elt(m(), m_guards, e);
m_trail.push(trail_elt);
}
SASSERT(!m_guards.contains(e));
m_guards.insert(e, empty());
m().inc_ref(e);
insert_ref_map<theory_recfun,guard_set,ast_manager,expr*> trail_elt(m(), m_guards, e);
m_trail.push(trail_elt);
if (m_guards.size() > get_max_depth()) {
// too many body-expansions: depth-limit conflict
max_depth_conflict();
@ -233,27 +231,37 @@ namespace smt {
return app_ref(u().mk_case_pred(p, args), m());
}
literal theory_recfun::mk_literal(expr* e) {
ctx().internalize(e, false);
literal lit = ctx().get_literal(e);
ctx().mark_as_relevant(lit);
return lit;
}
literal theory_recfun::mk_eq_lit(expr* l, expr* r) {
literal lit = mk_eq(l, r, false);
ctx().mark_as_relevant(lit);
return lit;
}
void theory_recfun::assert_macro_axiom(case_expansion & e) {
TRACEFN("assert_macro_axiom " << pp_case_expansion(e, m()));
SASSERT(e.m_def->is_fun_macro());
context & ctx = get_context();
auto & vars = e.m_def->get_vars();
expr_ref lhs(e.m_lhs, m());
// substitute `e.args` into the macro RHS
expr_ref rhs(apply_args(vars, e.m_args, e.m_def->get_macro_rhs()), m());
TRACEFN("macro expansion yields" << mk_pp(rhs,m()));
// add unit clause `lhs = rhs`
literal l(mk_eq(lhs, rhs, true));
ctx.mark_as_relevant(l);
TRACEFN("assert_macro_axiom: " << pp_lit(ctx, l));
ctx.mk_th_axiom(get_id(), 1, &l);
literal lit = mk_eq_lit(lhs, rhs);
TRACEFN("assert_macro_axiom: " << pp_lit(ctx(), lit));
ctx().mk_th_axiom(get_id(), 1, &lit);
}
void theory_recfun::assert_case_axioms(case_expansion & e) {
TRACEFN("assert_case_axioms "<< pp_case_expansion(e,m())
<< " with " << e.m_def->get_cases().size() << " cases");
SASSERT(e.m_def->is_fun_defined());
context & ctx = get_context();
// add case-axioms for all case-paths
auto & vars = e.m_def->get_vars();
for (recfun::case_def const & c : e.m_def->get_cases()) {
@ -261,24 +269,20 @@ namespace smt {
literal_vector guards;
for (auto & g : c.get_guards()) {
expr_ref guard = apply_args(vars, e.m_args, g);
ctx.internalize(guard, false);
guards.push_back(~ctx.get_literal(guard));
guards.push_back(~mk_literal(guard));
}
app_ref pred_applied = apply_pred(c.get_pred(), e.m_args);
SASSERT(u().owns_app(pred_applied));
ctx.internalize(pred_applied, false);
literal concl = ctx.get_literal(pred_applied);
ctx.mark_as_relevant(concl);
literal concl = mk_literal(pred_applied);
// assert `p(args) <=> And(guards)` (with CNF on the fly)
for (literal g : guards) {
literal c[2] = {~ concl, ~g};
ctx.mark_as_relevant(g);
get_context().mk_th_axiom(get_id(), 2, c);
ctx().mk_th_axiom(get_id(), 2, c);
}
guards.push_back(concl);
get_context().mk_th_axiom(get_id(), guards.size(), guards.c_ptr());
ctx().mk_th_axiom(get_id(), guards.size(), guards.c_ptr());
// also body-expand paths that do not depend on any defined fun
if (c.is_immediate()) {
@ -290,7 +294,6 @@ namespace smt {
void theory_recfun::assert_body_axiom(body_expansion & e) {
TRACEFN("assert_body_axioms "<< pp_body_expansion(e,m()));
context & ctx = get_context();
recfun::def & d = *e.m_cdef->get_def();
auto & vars = d.get_vars();
auto & args = e.m_args;
@ -307,16 +310,11 @@ namespace smt {
literal_vector clause;
for (auto & g : e.m_cdef->get_guards()) {
expr_ref guard = apply_args(vars, args, g);
ctx.internalize(guard, false);
literal l = ~ ctx.get_literal(guard);
ctx.mark_as_relevant(l);
clause.push_back(l);
clause.push_back(~mk_literal(guard));
}
literal l(mk_eq(lhs, rhs, true));
ctx.mark_as_relevant(l);
clause.push_back(l);
TRACEFN("assert_body_axiom " << pp_lits(ctx, clause));
ctx.mk_th_axiom(get_id(), clause.size(), clause.c_ptr());
clause.push_back(mk_eq_lit(lhs, rhs));
TRACEFN("assert_body_axiom " << pp_lits(ctx(), clause));
ctx().mk_th_axiom(get_id(), clause.size(), clause.c_ptr());
}
final_check_status theory_recfun::final_check_eh() {

2
src/smt/theory_recfun.h
View file

@ -121,6 +121,8 @@ namespace smt {
void assert_case_axioms(case_expansion & e);
void assert_body_axiom(body_expansion & e);
void max_depth_conflict(void);
literal mk_literal(expr* e);
literal mk_eq_lit(expr* l, expr* r);
protected:
void push_case_expand(case_expansion&& e) { m_q_case_expand.push_back(e); }
void push_body_expand(body_expansion&& e) { m_q_body_expand.push_back(e); }