SCIP
Solving Constraint Integer Programs
Solving Constraint Integer Programs
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"Go to the source code of this file.
Functions | |
| SCIP_RETCODE | SCIPincludePresolImplics (SCIP *scip) |