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[CP-SAT] work on lrat; better expansion of variables only appearing in encoding constraints

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This commit is contained in:
Laurent Perron
2025-11-17 16:42:09 +01:00
committed by Mizux Seiha
parent 6a1a8ceda6
commit 72d75ca109
37 changed files with 715 additions and 841 deletions
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23
ortools/sat/sat_solver.h
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@@ -38,7 +38,6 @@
#include "ortools/base/logging.h"
#include "ortools/base/timer.h"
#include "ortools/sat/clause.h"
#include "ortools/sat/drat_proof_handler.h"
#include "ortools/sat/enforcement.h"
#include "ortools/sat/lrat_proof_handler.h"
#include "ortools/sat/model.h"
@@ -126,12 +125,14 @@ class SatSolver {
// We call this a "problem" clause just because we will never delete such
// clause unless it is proven to always be satisfied. So this can be called
// with the initial clause of a problem, but also an inferred clause that we
// don't want to delete.
// don't want to delete (`shared` must be true iff the clause was inferred by
// another solver, from the same initial clauses).
//
// TODO(user): Rename this to AddClause() ? Also get rid of the specialized
// AddUnitClause(), AddBinaryClause() and AddTernaryClause() since they
// just end up calling this?
bool AddProblemClause(absl::Span<const Literal> literals);
bool AddProblemClause(absl::Span<const Literal> literals,
bool shared = false);
// Adds a pseudo-Boolean constraint to the problem. Returns false if the
// problem is detected to be UNSAT. If the constraint is always true, this
@@ -504,12 +505,6 @@ class SatSolver {
void SaveDebugAssignment();
void LoadDebugSolution(absl::Span<const Literal> solution);
void SetDratProofHandler(DratProofHandler* drat_proof_handler) {
drat_proof_handler_ = drat_proof_handler;
clauses_propagator_->SetDratProofHandler(drat_proof_handler_);
binary_implication_graph_->SetDratProofHandler(drat_proof_handler_);
}
// This function is here to deal with the case where a SAT/CP model is found
// to be trivially UNSAT while the user is constructing the model. Instead of
// having to test the status of all the lines adding a constraint, one can
@@ -663,7 +658,8 @@ class SatSolver {
// Add a problem clause. The clause is assumed to be "cleaned", that is no
// duplicate variables (not strictly required) and not empty.
bool AddProblemClauseInternal(absl::Span<const Literal> literals);
bool AddProblemClauseInternal(absl::Span<const Literal> literals,
bool shared = false);
// This is used by all the Add*LinearConstraint() functions. It detects
// infeasible/trivial constraints or clause constraints and takes the proper
@@ -694,9 +690,6 @@ class SatSolver {
// Update the propagators_ list with the relevant propagators.
void InitializePropagators();
// Output to the DRAT proof handler any newly fixed variables.
void ProcessNewlyFixedVariablesForDratProof();
// Returns the maximum trail_index of the literals in the given clause.
// All the literals must be assigned. Returns -1 if the clause is empty.
int ComputeMaxTrailIndex(absl::Span<const Literal> clause) const;
@@ -877,9 +870,6 @@ class SatSolver {
int num_processed_fixed_variables_ = 0;
double deterministic_time_of_last_fixed_variables_cleanup_ = 0.0;
// Used in ProcessNewlyFixedVariablesForDratProof().
int drat_num_processed_fixed_variables_ = 0;
Counters counters_;
// Solver information.
@@ -950,7 +940,6 @@ class SatSolver {
// it is necessary to keep track of the last time the time was advanced.
double deterministic_time_at_last_advanced_time_limit_ = 0;
DratProofHandler* drat_proof_handler_ = nullptr;
LratProofHandler* lrat_proof_handler_ = nullptr;
mutable StatsGroup stats_;