Dear Osi, Do there is any function I can verify (after solving an LP) if a column is nonbasic ? (or if it is basic ?) Thank you, Flavio -- Flavio Keidi Miyazawa Institute of Computing -- UNICAMP Phone: +55.19.3788-5882 Fax: +55.19.3788-5847 Email: fkm at ic.unicamp.br url: http://www.ic.unicamp.br/~fkm