feasible solution (verify with TORA!). On the other hand, the use of the inequality is inclusive
of the equality case, and hence its use does not prevent the model from producing exactly 800 Ib
of feed mix, should the remaining constraints allow it. TI1e conclusion is that we should not "preguess"
the solution by imposing the additional equality restriction, and we should always use inequalities
unless the situation explicitly stipulates the use of equalities.