The procedure dual(f, C, y) computes the dual of a linear program which is in standard inequality form.

The expression f is the linear objective function to be maximized, subject to the linear inequalities C. These inequalities are in the special form produced by simplex[convert/stdle]. The name y is used to construct the names y1, y2, ... for the dual variables.

The resulting dual is returned as an expression sequence:  objective, constraints.

The command with(simplex,dual) allows the use of the abbreviated form of this command.