@Markiyan Hirnyk If I understood correctly, multiplicity of solutions in primal program does not necessarily mean that the solution of the dual is degenerate. If I am correct, solving dual program will not resolve my problem. If solution of dual is not degenerate it will be not possible to say if the solution of primal is unique. Is it right?

@Markiyan Hirnyk If I understood correctly, multiplicity of solutions in primal program does not necessarily mean that the solution of the dual is degenerate. If I am correct, solving dual program will not resolve my problem. If solution of dual is not degenerate it will be not possible to say if the solution of primal is unique. Is it right?

Could you please clarify your point with duality? I do not see why two zeros indicate non uniqueness.

Could you please clarify your point with duality? I do not see why two zeros indicate non uniqueness.

I have Maple 15.01 under Windows. On my computer this simple example sometimes works and sometimes does not. For more complicated problems I always recieve error message.

I have Maple 15.01 under Windows. On my computer this simple example sometimes works and sometimes does not. For more complicated problems I always recieve error message.

This is the example: with "method = activeset" it works and with  "method = interiorpoint" it does not.

> LPSolve(x+y, {x <= 3/2, x+y <= 2}, assume = nonnegative, maximize, method = interiorpoint);
Error, (in Optimization:-LPSolve) unrecognized storage format, storage = []

> LPSolve(x+y, {x <= 3/2, x+y <= 2}, assume = nonnegative, maximize, method = activeset);
            [2., [x = HFloat(1.5), y = HFloat(0.5)]]