Description

The following checks have to be performed:

1. If the objective equation is unambiguous it cannot be involved in a disjunction.
2. If there are multiple the reader has to make sure each term of the relevant
disjunction has to have a (potential) objective

Contributor: Jan-H. Jagla, November 2010

Small Model of Type : GAMS

Category : GAMS Test library

Main file : empdisj2.gms

$title Test disjunctions involving the objective (EMPDISJ2,SEQ=501)

$onText
The following checks have to be performed:

1. If the objective equation is unambiguous it cannot be involved in a disjunction.
2. If there are multiple the reader has to make sure each term of the relevant
disjunction has to have a (potential) objective

Contributor: Jan-H. Jagla, November 2010
$offText

variable x; equation e1,e2,e3; model m  / all /;
variable y; equation e1a,e3a ; model m2 / all /;
                               model m3 / e1,e2,e3,e1a /;

e1.. x =e= 1;
e1a.. y =e= 1;
e2.. x =e= 2;
e3.. x =e= 3;
e3a.. y =e= 3;

file fhandle /"%emp.info%"/;

*This is ok since every term has an obj
putclose fhandle 'disjunction bigm * e1 elseif * e2 else e3';
solve m us emp min x;
abort$(m.solvestat <> 1 or m.modelstat <> 1) '1st solve should terminate with (1,1)';

*This is NOT ok since the second term has no obj
putclose fhandle 'disjunction bigm * e1 e1a elseif * e2 else e3 e3a';
solve m2 us emp min y;
abort$(m2.solvestat <> 12 or m2.modelstat <> 14) '2nd solve should terminate with (12,14)';

*This is ok since obj is not involved a disjunction
putclose fhandle 'disjunction bigm * e1 elseif * e2 else e3';
solve m3 us emp min y;
abort$(m3.solvestat <> 1 or m3.modelstat <> 1) '3rd solve should terminate with (1,1)';

*This is NOT ok since the objective is unambiguous and involved
*in a disjunction hence only one term involves and has an obj
putclose fhandle 'disjunction bigm * e1 e1a elseif * e2 else e3';
solve m3 us emp min y;
abort$(m3.solvestat <> 12 or m3.modelstat <> 14) '4th solve should terminate with (12,14)';