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add rewrite for mod over negation, refine axioms for grobner quotients

This commit is contained in:
Nikolaj Bjorner 2025-09-02 18:26:22 -07:00
parent e2235d81d3
commit a382ddbd8a
4 changed files with 95 additions and 66 deletions

View file

@ -601,6 +601,12 @@ class theory_lra::imp {
ctx().mk_th_axiom(get_id(), l1, l2, l3, num_params, params);
}
void mk_clause(literal l1, literal l2, literal l3, literal l4, unsigned num_params, parameter* params) {
literal clause[4] = { l1, l2, l3, l4 };
TRACE(arith, ctx().display_literals_smt2(tout, 4, clause); tout << "\n";);
ctx().mk_th_axiom(get_id(), 4, clause, num_params, params);
}
bool reflect(app* n) const {
return params().m_arith_reflect || a.is_underspecified(n);
@ -1288,6 +1294,7 @@ public:
else {
expr_ref mone(a.mk_int(-1), m);
expr_ref minus_q(a.mk_mul(mone, q), m);
literal eqz = mk_literal(m.mk_eq(q, zero));
literal mod_ge_0 = mk_literal(a.mk_ge(mod, zero));
@ -1296,12 +1303,13 @@ public:
// q = 0 or (p mod q) >= 0
// q >= 0 or (p mod q) + q <= -1
// q <= 0 or (p mod q) - q <= -1
// (p mod q) = (p mod -q)
mk_axiom(eqz, eq);
mk_axiom(eqz, mod_ge_0);
mk_axiom(mk_literal(a.mk_le(q, zero)), mk_literal(a.mk_le(a.mk_add(mod, a.mk_mul(mone, q)), mone)));
mk_axiom(mk_literal(a.mk_le(q, zero)), mk_literal(a.mk_le(a.mk_add(mod, minus_q), mone)));
mk_axiom(mk_literal(a.mk_ge(q, zero)), mk_literal(a.mk_le(a.mk_add(mod, q), mone)));
expr* x = nullptr, * y = nullptr;
if (false && !(a.is_mul(q, x, y) && mone == x))
mk_axiom(mk_literal(m.mk_eq(mod, a.mk_mod(p, a.mk_mul(mone, q)))));
@ -1420,12 +1428,21 @@ public:
}
}
void mk_axiom(literal l1, literal l2, literal l3, literal l4) {
mk_clause(l1, l2, l3, l4, 0, nullptr);
if (ctx().relevancy()) {
ctx().mark_as_relevant(l1);
ctx().mark_as_relevant(l2);
ctx().mark_as_relevant(l3);
ctx().mark_as_relevant(l4);
}
}
literal mk_literal(expr* e) {
expr_ref pinned(e, m);
TRACE(mk_bool_var, tout << pinned << " " << pinned->get_id() << "\n";);
if (!ctx().e_internalized(e)) {
ctx().internalize(e, false);
}
if (!ctx().e_internalized(e))
ctx().internalize(e, false);
return ctx().get_literal(e);
}