GLPK finds a solution that violates a constraint

Evgeny Kapun <[email protected]> Mon, 28 Jun 2021 00:51:26 +0300

Newsgroups	gmane.comp.gnu.glpk
Message-ID	<[email protected]>

I have a model (attached). It includes a constraint:

> s.t. contra : x - y + 1000000 * z <= 1000000;

When I solve it (using glpsol --math model.sol), I get a solution with x=20, y=10 and z=1, which clearly violates that constraint. Why is it happening?

model.mod (application/xml-dtd, 510 B) - not displayed