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add rewrites for moduli as exercised in example from #2319

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-11-24 19:02:28 -08:00
parent fad4356159
commit 84025d5c11
4 changed files with 61 additions and 39 deletions
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51
src/tactic/core/solve_eqs_tactic.cpp
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@ -327,28 +327,53 @@ class solve_eqs_tactic : public tactic {
pr = m().mk_rewrite(eq, m().mk_eq(var, def));
return true;
}
bool solve_mod(expr * lhs, expr * rhs, expr * eq, app_ref & var, expr_ref & def, proof_ref & pr) {
rational r1, r2;
expr* arg1, *arg2, *arg3, *arg4;
if (m_produce_proofs) {
return false;
}
VERIFY(m_a_util.is_mod(lhs, arg1, arg2));
if (!m_a_util.is_numeral(arg2, r1) || !r1.is_pos()) {
return false;
}
if (m_a_util.is_mod(rhs, arg3, arg4) && m_a_util.is_numeral(arg4, r2) && r1 == r2) {
rhs = arg3;
}
else if (!m_a_util.is_numeral(rhs, r2) || !r2.is_zero()) {
return false;
}
if (solve_eq(arg1, rhs, eq, var, def, pr)) {
def = m_a_util.mk_add(def, m_a_util.mk_mul(m().mk_fresh_const("mod", m_a_util.mk_int()), m_a_util.mk_int(r1)));
return true;
}
return false;
}
bool solve_arith(expr * lhs, expr * rhs, expr * eq, app_ref & var, expr_ref & def, proof_ref & pr) {
return
(m_a_util.is_add(lhs) && solve_arith_core(to_app(lhs), rhs, eq, var, def, pr)) ||
(m_a_util.is_add(rhs) && solve_arith_core(to_app(rhs), lhs, eq, var, def, pr));
#if 0
// better done inside of nlsat
(m_a_util.is_add(lhs) && solve_nl(to_app(lhs), rhs, eq, var, def, pr)) ||
(m_a_util.is_add(rhs) && solve_nl(to_app(rhs), lhs, eq, var, def, pr));
#endif
(m_a_util.is_add(rhs) && solve_arith_core(to_app(rhs), lhs, eq, var, def, pr)) ||
(m_a_util.is_mod(lhs) && solve_mod(lhs, rhs, eq, var, def, pr)) ||
(m_a_util.is_mod(rhs) && solve_mod(rhs, lhs, eq, var, def, pr));
}
bool solve_eq(expr* arg1, expr* arg2, expr* eq, app_ref& var, expr_ref & def, proof_ref& pr) {
if (trivial_solve(arg1, arg2, var, def, pr))
return true;
if (m_theory_solver) {
if (solve_arith(arg1, arg2, eq, var, def, pr))
return true;
}
return false;
}
bool solve(expr * f, app_ref & var, expr_ref & def, proof_ref & pr) {
expr* arg1 = nullptr, *arg2 = nullptr;
if (m().is_eq(f, arg1, arg2)) {
if (trivial_solve(arg1, arg2, var, def, pr))
return true;
if (m_theory_solver) {
if (solve_arith(arg1, arg2, f, var, def, pr))
return true;
}
return false;
return solve_eq(arg1, arg2, f, var, def, pr);
}
#if 0