mip04.gms : Exercise new XPRESS return code for unbounded MIP

Description

In the model we make sure the XPRESS link is properly handling the
XPRS_MIP_UNBOUNDED code - new in XPVERSION 22.

Contributor: Steve Dirkse, May 2011


Small Model of Type : MIP


Category : GAMS Test library


Main file : mip04.gms

$title Exercise new XPRESS return code for unbounded MIP (MIP04,SEQ=525)

$ontext
In the model we make sure the XPRESS link is properly handling the
XPRS_MIP_UNBOUNDED code - new in XPVERSION 22.

Contributor: Steve Dirkse, May 2011
$offtext


variable x, y, z;
equations f, g;

f.. z =e= x + 2*y;
g.. x - 2*y =L= 2;

model m / f, g /;

solve m using mip max z;
abort$[m.solvestat <> %solvestat.NormalCompletion%] 'Unexpected solvestat', m.solvestat;
abort$[(m.modelstat <> %modelstat.Unbounded%) and (m.modelstat <> %modelstat.Unbounded - No Solution%)] 'Unexpected modelstat', m.modelstat;