Terminology
The variables x1. . . , xn are called decision variables of the
problem. The linear function to optimize is called function
objective (or function object). The constraints take the form of
linear equations and inequations.
lj = xj = uj lj, uj ? R U {±8 }
are called terminals constraints, they are often summarized with
constraints of nonnegativity xj = 0 and are generally treated in a
special way by the algorithms of resolution.