Detailed Description

implication graph presolver which checks for aggregations

This presolver looks for variable implications in $x == 0$ and $x == 1$ with the same implied variable. There are four possible cases:

$x = 0 \Rightarrow y = lb,\; \mathrm{and}\; x = 1 \Rightarrow y = lb:\; \mathrm{fix}\; y\; \mathrm{to}\; lb$

$x = 0 \Rightarrow y = lb,\; \mathrm{and}\; x = 1 \Rightarrow y = ub:\; \mathrm{aggregate}\; y == lb + (ub-lb)x$

$x = 0 \Rightarrow y = ub,\; \mathrm{and}\; x = 1 \Rightarrow y = lb:\; \mathrm{aggregate}\; y == ub - (ub-lb)x$

$x = 0 \Rightarrow y = ub,\; \mathrm{and}\; x = 1 \Rightarrow y = ub:\; \mathrm{fix}\; y\; \mathrm{to}\; ub$

Definition in file presol_implics.h.

#include "scip/scip.h"

Functions
SCIP_RETCODE	SCIPincludePresolImplics (SCIP *scip)

Function Documentation

SCIP_RETCODE SCIPincludePresolImplics ( SCIP * scip )

creates the implics presolver and includes it in SCIP

Parameters

scip	SCIP data structure