mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-08-11 05:30:51 +00:00
Code Activity

add option to bypass model converter during constraint addition. Simplify model definitions that come from blocked clauses

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-11-27 16:24:14 -08:00
parent 1101c927c9
commit fbae881ece
5 changed files with 65 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

35
src/tactic/generic_model_converter.cpp
View file

@ -20,6 +20,8 @@ Notes:
#include "ast/ast_pp.h"
#include "ast/for_each_expr.h"
#include "ast/ast_util.h"
#include "ast/occurs.h"
#include "ast/rewriter/expr_safe_replace.h"
#include "tactic/generic_model_converter.h"
#include "model/model_v2_pp.h"
#include "model/model_evaluator.h"
@ -110,7 +112,7 @@ void generic_model_converter::operator()(expr_ref& fml) {
entry const& e = m_add_entries[i];
unsigned arity = e.m_f->get_arity();
if (arity == 0) {
fmls.push_back(m.mk_eq(m.mk_const(e.m_f), e.m_def));
fmls.push_back(simplify_def(e));
}
else {
expr_ref_vector args(m);
@ -133,3 +135,34 @@ void generic_model_converter::operator()(expr_ref& fml) {
}
fml = mk_and(fmls);
}
/*
\brief simplify definition expansion from model converter in the case they come from blocked clauses.
In this case the definitions are of the form:
x <=> x or not (C)
or dually,
x <=> not (not x or not C)
in either case the definitions simplify to
x or C
*/
expr_ref generic_model_converter::simplify_def(entry const& e) {
expr_ref result(m);
expr_ref c(m.mk_const(e.m_f), m);
if (m.is_bool(c) && occurs(c, e.m_def)) {
expr_safe_replace rep(m);
expr_ref result1 = e.m_def;
expr_ref result2 = e.m_def;
rep.apply_substitution(c, m.mk_true(), result1);
rep.apply_substitution(c, m.mk_false(), result2);
return expr_ref(m.mk_and(m.mk_or(c, result2), m.mk_or(m.mk_not(c), result1)), m);
}
else {
return expr_ref(m.mk_eq(c, e.m_def), m);
}
}