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fix incorrect bound in order-lemma

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-06-13 14:28:15 -07:00
parent 23c12b75af
commit 5ee9edf46b
6 changed files with 34 additions and 28 deletions
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42
src/math/lp/nla_order_lemmas.cpp
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@ -227,25 +227,22 @@ void order::order_lemma_on_factorization(const monic& m, const factorization& ab
}
}
bool order::order_lemma_on_ac_explore(const monic& rm, const factorization& ac, bool k) {
void order::order_lemma_on_ac_explore(const monic& rm, const factorization& ac, bool k) {
const factor c = ac[k];
TRACE("nla_solver", tout << "c = "; _().print_factor_with_vars(c, tout); );
if (c.is_var()) {
TRACE("nla_solver", tout << "var(c) = " << var(c););
for (monic const& bc : _().emons().get_use_list(c.var())) {
if (order_lemma_on_ac_and_bc(rm, ac, k, bc)) {
return true;
}
if (order_lemma_on_ac_and_bc(rm, ac, k, bc))
return;
}
}
else {
for (monic const& bc : _().emons().get_products_of(c.var())) {
if (order_lemma_on_ac_and_bc(rm, ac, k, bc)) {
return true;
}
if (order_lemma_on_ac_and_bc(rm, ac, k, bc))
return;
}
}
return false;
}
void order::generate_ol_eq(const monic& ac,
@ -280,15 +277,19 @@ void order::generate_ol(const monic& ac,
const factor& b) {
new_lemma lemma(_(), __FUNCTION__);
IF_VERBOSE(100, verbose_stream() << var_val(ac) << "(" << mul_val(ac) << "): " << ac
TRACE("nla_solver", _().trace_print_ol(ac, a, c, bc, b, tout););
IF_VERBOSE(10, verbose_stream() << var_val(ac) << "(" << mul_val(ac) << "): " << ac
<< " " << var_val(bc) << "(" << mul_val(bc) << "): " << bc << "\n"
<< " a " << "*v" << var(a) << " " << val(a) << "\n"
<< " b " << "*v" << var(b) << " " << val(b) << "\n"
<< " c " << "*v" << var(c) << " " << val(c) << "\n");
// fix the sign of c
// c > 0 and ac >= bc => a >= b
// c > 0 and ac <= bc => a <= b
// c < 0 and ac >= bc => a <= b
// c < 0 and ac <= bc => a >= b
lemma |= ineq(c.var(), val(c.var()).is_neg() ? llc::GE : llc::LE, 0);
_().negate_var_relation_strictly(lemma, ac.var(), bc.var());
_().negate_var_relation_strictly(lemma, a.var(), b.var());
lemma |= ineq(term(ac.var(), -rational(1), bc.var()), val(ac.var()) < val(bc.var()) ? llc::GT : llc::LT, 0);
lemma |= ineq(term(a.var(), -rational(1), b.var()), val(a.var()) < val(b.var()) ? llc::GE : llc::LE, 0);
lemma &= ac;
lemma &= a;
@ -298,8 +299,9 @@ void order::generate_ol(const monic& ac,
}
// We have ac = a*c and bc = b*c.
// Suppose ac >= bc, then ac/|c| >= bc/|b|
// Notice that ac/|c| = a*rat_sign(val(c)|, and similar fo bc/|c|.//
// Suppose ac >= bc, then ac/|c| >= bc/|c|
// Notice that ac/|c| = a*rat_sign(val(c)|, and similar fo bc/|c|.
//
bool order::order_lemma_on_ac_and_bc_and_factors(const monic& ac,
const factor& a,
const factor& c,
@ -309,16 +311,14 @@ bool order::order_lemma_on_ac_and_bc_and_factors(const monic& ac,
rational c_sign = rational(nla::rat_sign(val(c)));
auto av_c_s = val(a) * c_sign;
auto bv_c_s = val(b) * c_sign;
if ((var_val(ac) > var_val(bc) && av_c_s < bv_c_s)
||
if ((var_val(ac) > var_val(bc) && av_c_s < bv_c_s) ||
(var_val(ac) < var_val(bc) && av_c_s > bv_c_s)) {
TRACE("nla_solver", _().trace_print_ol(ac, a, c, bc, b, tout););
generate_ol(ac, a, c, bc, b);
return true;
} else {
if ((var_val(ac) == var_val(bc)) && (av_c_s != bv_c_s)) {
generate_ol_eq(ac, a, c, bc, b);
}
}
else if ((var_val(ac) == var_val(bc)) && (av_c_s != bv_c_s)) {
generate_ol_eq(ac, a, c, bc, b);
return true;
}
return false;
}