Description

This test is based on bug report send by Silvia Tomasi.

The disjunctive program to solve is
minimize x
such that (A1 or (x=0)) and
          (not A2 or not (x <= 3)) and
          (not A1 or A2)

An optimal solution is x = 0:
A1 = false, A2 = false, (x=0) = true, (x<=3) = true.

Contributor: Stefan Vigerske, November 2012

Small Model of Type : GAMS

Category : GAMS Test library

Main file : empdisj6.gms

$title Test disjunctions using negated equality equations (EMPDISJ6, SEQ=581)
$onText
This test is based on bug report send by Silvia Tomasi.

The disjunctive program to solve is
minimize x
such that (A1 or (x=0)) and
          (not A2 or not (x <= 3)) and
          (not A1 or A2)

An optimal solution is x = 0:
A1 = false, A2 = false, (x=0) = true, (x<=3) = true.

Contributor: Stefan Vigerske, November 2012
$offText

$if not set TESTTOL $set TESTTOL 1e-6

variables z, x;
binary variables A1, A2, A3, A4;

equations e0, e1, e2, e3, e4;

e0.. z  =e= x;
e1.. A1 =e= 1;
e2.. A2 =e= 1;
e3.. x  =e= 0;
e4.. x  =l= 3;

model m / all /;

option optcr = 0;

set forms / bigm, indic /;

file empinfo / '%emp.info%' /;
loop(forms,
 put empinfo;
 put 'default ' forms.tl /;
 put 'disjunction * e1 else e3' /;
 put 'disjunction * Not e2 else Not e4' /;
 put 'disjunction * Not e1 else e2';
 putclose;

 solve m us emp min z;

 abort$(abs(z.l) > %TESTTOL%) "wrong optimal value, expected 0"
 abort$(abs(x.l) > %TESTTOL%) "wrong solution value for x, expected 0"
);