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port Grobner

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Signed-off-by: Lev Nachmanson <levnach@hotmail.com>
This commit is contained in:
Lev Nachmanson 2019-10-16 16:59:39 -07:00
parent 35c4b07bc4
commit f8059394e5
4 changed files with 38 additions and 33 deletions
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41
src/math/grobner/grobner.cpp
View file

@ -586,25 +586,20 @@ grobner::equation * grobner::copy_equation(equation const * eq) {
// source 3f + k = 0, so f = -k/3
// target 2fg + e = 0
// target is replaced by 2(-k/3)g + e = -2/3kg + e
unsigned grobner::simplify_loop_on_target_monomials(equation const * source, equation * target, bool & result) {
bool grobner::simplify_target_monomials(equation const * source, equation * target) {
unsigned i = 0;
unsigned new_target_sz = 0;
unsigned sz = target->m_monomials.size();
unsigned target_sz = target->m_monomials.size();
monomial const * LT = source->get_monomial(0);
m_tmp_monomials.reset();
for (; i < sz; i++) {
for (; i < target_sz; i++) {
monomial * targ_i = target->m_monomials[i];
if (divide_ignore_coeffs(targ_i, LT)) {
if (i == 0)
m_changed_leading_term = true;
if (!result) { // first time that source is being applied.
target->m_dep = m_dep_manager.mk_join(target->m_dep, source->m_dep);
result = true;
}
rational coeff = - targ_i->m_coeff / (LT->m_coeff);
if (!m_tmp_vars1.empty())
target->m_lc = false;
mul_append_skip_first(source, coeff, m_tmp_vars1);
mul_append_skip_first(source, - targ_i->m_coeff / (LT->m_coeff), m_tmp_vars1);
del_monomial(targ_i);
}
else {
@ -614,16 +609,20 @@ unsigned grobner::simplify_loop_on_target_monomials(equation const * source, equ
new_target_sz++;
}
}
return new_target_sz;
if (new_target_sz < target_sz) {
target->m_monomials.shrink(new_target_sz);
target->m_monomials.append(m_tmp_monomials.size(), m_tmp_monomials.c_ptr());
simplify_eq(target);
TRACE("grobner", tout << "result: "; display_equation(tout, *target););
return true;
}
return false;
}
/**
\brief Simplify the target equation using the source as a rewrite rule.
Return 0 if target was not simplified.
LN. The rest of the comment seems to be incorrect: there is no m_scope_lvl
Return target if target was simplified
Return new_equation if source->m_scope_lvl > target->m_scope_lvl, moreover target is freezed, and new_equation contains the result.
*/
grobner::equation * grobner::simplify_source_target(equation const * source, equation * target) {
TRACE("grobner", tout << "simplifying: "; display_equation(tout, *target); tout << "using: "; display_equation(tout, *source););
@ -632,18 +631,18 @@ grobner::equation * grobner::simplify_source_target(equation const * source, equ
m_stats.m_simplify++;
bool result = false;
do {
unsigned target_new_size = simplify_loop_on_target_monomials(source, target, result);
if (target_new_size < target->m_monomials.size()) {
target->m_monomials.shrink(target_new_size);
target->m_monomials.append(m_tmp_monomials.size(), m_tmp_monomials.c_ptr());
simplify_eq(target);
if (simplify_target_monomials(source, target)) {
result = true;
} else {
break;
}
}
while (!m_manager.canceled());
} while (!m_manager.canceled());
TRACE("grobner", tout << "result: "; display_equation(tout, *target););
return result ? target : nullptr;
if (result) {
target->m_dep = m_dep_manager.mk_join(target->m_dep, source->m_dep);
return target;
}
return nullptr;
}
/**

2
src/math/grobner/grobner.h
View file

@ -166,7 +166,7 @@ protected:
equation * copy_equation(equation const * eq);
equation * simplify_source_target(equation const * source, equation * target);
unsigned simplify_loop_on_target_monomials(equation const * source, equation * target, bool&);
bool simplify_target_monomials(equation const * source, equation * target);
equation * simplify_using_processed(equation * eq);