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z3/src/math/lp/nla_monotone_lemmas.cpp
Lev Nachmanson 38eca3b66a fixes in order lemmas and printing terms
Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
2020-03-25 19:43:55 -07:00

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1.9 KiB
C++

/*++
Copyright (c) 2017 Microsoft Corporation
Module Name:
<name>
Abstract:
<abstract>
Author:
Nikolaj Bjorner (nbjorner)
Lev Nachmanson (levnach)
Revision History:
--*/
#include "math/lp/nla_basics_lemmas.h"
#include "math/lp/nla_core.h"
namespace nla {
monotone::monotone(core * c) : common(c) {}
void monotone::monotonicity_lemma() {
unsigned shift = random();
unsigned size = c().m_to_refine.size();
for(unsigned i = 0; i < size && !done(); i++) {
lpvar v = c().m_to_refine[(i + shift) % size];
monotonicity_lemma(c().emons()[v]);
}
}
void monotone::monotonicity_lemma(monic const& m) {
SASSERT(!check_monic(m));
if (c().mon_has_zero(m.vars()))
return;
const rational prod_val = abs(c().product_value(m));
const rational m_val = abs(var_val(m));
if (m_val < prod_val)
monotonicity_lemma_lt(m, prod_val);
else if (m_val > prod_val)
monotonicity_lemma_gt(m, prod_val);
}
void monotone::monotonicity_lemma_gt(const monic& m, const rational& prod_val) {
TRACE("nla_solver", tout << "prod_val = " << prod_val << "\n";
tout << "m = "; c().print_monic_with_vars(m, tout););
add_empty_lemma();
for (lpvar j : m.vars()) {
c().add_abs_bound(j, llc::GT);
}
lpvar m_j = m.var();
c().add_abs_bound(m_j, llc::LE, prod_val);
TRACE("nla_solver", print_lemma(tout););
}
/** \brief enforce the inequality |m| >= product |m[i]| .
/\_i |m[i]| >= |val(m[i])| => |m| >= |product_i val(m[i])|
<=>
\/_i |m[i]| < |val(m[i])} or |m| >= |product_i val(m[i])|
*/
void monotone::monotonicity_lemma_lt(const monic& m, const rational& prod_val) {
add_empty_lemma();
for (lpvar j : m.vars()) {
c().add_abs_bound(j, llc::LT);
}
lpvar m_j = m.var();
c().add_abs_bound(m_j, llc::GE, prod_val);
TRACE("nla_solver", print_lemma(tout););
}
}