operations_research::sat::BinaryRelationRepository Class Reference

#include <precedences.h>

Public Member Functions
int	size () const
const Relation &	relation (int index) const
absl::Span< const int >	relation_indices (LiteralIndex lit) const
void	Add (Literal lit, LinearTerm a, LinearTerm b, IntegerValue lhs, IntegerValue rhs)
	Adds a relation lit => a + b \in [lhs, rhs].
void	Build ()
bool	PropagateLocalBounds (const IntegerTrail &integer_trail, Literal lit, const absl::flat_hash_map< IntegerVariable, IntegerValue > &input, absl::flat_hash_map< IntegerVariable, IntegerValue > *output) const

Detailed Description

A repository of all the enforced linear constraints of size 1 or 2.

Todo

(user): This is not always needed, find a way to clean this once we don't need it.

Definition at line 494 of file precedences.h.

Member Function Documentation

Add()

void operations_research::sat::BinaryRelationRepository::Add	(	Literal	lit,
		LinearTerm	a,
		LinearTerm	b,
		IntegerValue	lhs,
		IntegerValue	rhs )

Adds a relation lit => a + b \in [lhs, rhs].

We shall only consider positive variable here.

Definition at line 1108 of file precedences.cc.

Build()

void operations_research::sat::BinaryRelationRepository::Build

(

)

Builds the literal to relations mapping. This should be called once all the relations have been added.

Definition at line 1130 of file precedences.cc.

PropagateLocalBounds()

bool operations_research::sat::BinaryRelationRepository::PropagateLocalBounds	(	const IntegerTrail &	integer_trail,
		Literal	lit,
		const absl::flat_hash_map< IntegerVariable, IntegerValue > &	input,
		absl::flat_hash_map< IntegerVariable, IntegerValue > *	output ) const

Assuming level-zero bounds + any (var >= value) in the input map, fills "output" with a "propagated" set of bounds assuming lit is true (by using the relations enforced by lit). Note that we will only fill bounds > level-zero ones in output.

Returns false if the new bounds are infeasible at level zero.

lb(b.y) <= b.y <= ub(b.y) and lhs <= a.x + b.y <= rhs imply ceil((lhs - ub(b.y)) / a) <= x <= floor((rhs - lb(b.y)) / a)

Check feasibility.

Todo

(user): we might do that earlier?

Definition at line 1391 of file precedences.cc.

relation()

const Relation & operations_research::sat::BinaryRelationRepository::relation ( int index ) const

inline

Definition at line 497 of file precedences.h.

relation_indices()

absl::Span< const int > operations_research::sat::BinaryRelationRepository::relation_indices ( LiteralIndex lit ) const

inline

Definition at line 499 of file precedences.h.

size()

int operations_research::sat::BinaryRelationRepository::size ( ) const

inline

Definition at line 496 of file precedences.h.

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The documentation for this class was generated from the following files:

• ortools/sat/precedences.h
• ortools/sat/precedences.cc