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Option use_implied_bounds_from_presolve is now redundant #3311

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Merged
jajhall merged 1 commit into from
Sep 23, 2026
+6 −47
Merged

Option use_implied_bounds_from_presolve is now redundant #3311

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9 changes: 5 additions & 4 deletions check/TestPresolve.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1261,7 +1261,7 @@ TEST_CASE("test-fuzzing", "[highs_test_presolve]") {
// if (dev_run) {
printf("\n====================\nWithout presolve\n====================\n");

const std::string model = "issue-009";
const std::string model = "issue-010";
std::string model_file = std::string(HIGHS_DIR) + "/build/OscarFuzzing/" +
model + "/" + model + ".mps";

Expand All @@ -1281,9 +1281,10 @@ TEST_CASE("test-fuzzing", "[highs_test_presolve]") {
std::string options_file =
std::string(HIGHS_DIR) + "/build/OscarFuzzing/" + model + "/options.txt";
REQUIRE(h.readOptions(options_file) == HighsStatus::kOk);
// REQUIRE(h.setOptionValue("presolve_rule_off", 1 <<
kPresolveRuleColStuffing) == HighsStatus::kOk); HighsOptions options =
h.getOptions();

// REQUIRE(h.setOptionValue("presolve_rule_off", 1 << kPresolveRuleColStuffing) == HighsStatus::kOk);

HighsOptions options = h.getOptions();

printf("\n====================\nPresolved LP\n====================\n");
h.presolve();
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2 changes: 1 addition & 1 deletion highs/lp_data/HighsOptions.h
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Expand Up @@ -1500,7 +1500,7 @@ class HighsOptions : public HighsOptionsStruct {

record_bool = new OptionRecordBool(
"use_implied_bounds_from_presolve",
"Use relaxed implied bounds from presolve", advanced,
"Use relaxed implied bounds from presolve: redundant option!", advanced,
&use_implied_bounds_from_presolve, false);
records.push_back(record_bool);

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40 changes: 0 additions & 40 deletions highs/presolve/HPresolve.cpp
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Expand Up @@ -7114,9 +7114,6 @@ HighsModelStatus HPresolve::run(HighsPostsolveStack& postsolve_stack) {
presolve_status_ = HighsPresolveStatus::kNotReduced;
}

if (!mipsolver && options->use_implied_bounds_from_presolve)
setRelaxedImpliedBounds();

assert(presolve_status_ != HighsPresolveStatus::kNotSet);
return HighsModelStatus::kNotset;
}
Expand Down Expand Up @@ -9578,43 +9575,6 @@ HPresolve::Result HPresolve::equalityRowAddition(
return Result::kOk;
}

void HPresolve::setRelaxedImpliedBounds() {
double hugeBound = primal_feastol / kHighsTiny;
for (HighsInt i = 0; i != model->num_col_; ++i) {
if (model->col_lower_[i] >= implColLower[i] &&
model->col_upper_[i] <= implColUpper[i])
continue;

if (std::abs(implColLower[i]) <= hugeBound) {
// if the bound is derived from a small nonzero value
// then we want to increase the margin so that we make sure
// the row it was derived from is violated if the column sits
// at this relaxed bound in the final solution.
HighsInt nzPos = findNonzero(colLowerSource[i], i);

double boundRelax = std::max(1000.0, std::abs(implColLower[i])) *
primal_feastol /
std::min(1.0, std::abs(Avalue[nzPos]));

double newLb = implColLower[i] - boundRelax;
if (newLb > model->col_lower_[i] + boundRelax)
model->col_lower_[i] = newLb;
}

if (std::abs(implColUpper[i]) <= hugeBound) {
HighsInt nzPos = findNonzero(colUpperSource[i], i);

double boundRelax = std::max(1000.0, std::abs(implColUpper[i])) *
primal_feastol /
std::min(1.0, std::abs(Avalue[nzPos]));

double newUb = implColUpper[i] + boundRelax;
if (newUb < model->col_upper_[i] - boundRelax)
model->col_upper_[i] = newUb;
}
}
}

void HPresolve::extractVarBounds(HighsInt row) {
// extract variable bound constraints from the row

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2 changes: 0 additions & 2 deletions highs/presolve/HPresolve.h
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Expand Up @@ -523,8 +523,6 @@ class HPresolve {

Result sparsify(HighsPostsolveStack& postsolve_stack);

void setRelaxedImpliedBounds();

const HighsPresolveLog& getPresolveLog() const {
return analysis_.presolve_log_;
}
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