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 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.

$\mathrm{with}\left(\mathrm{simplex}\right)\:$

$\mathrm{dual}\left(x+y\,\left\{3x+4y\le 4\,4x+3y\le 5\right\}\,z\right)$

$4\mathrm{z1}+5\mathrm{z2},\left\{1\le 3\mathrm{z1}+4\mathrm{z2}\,1\le 4\mathrm{z1}+3\mathrm{z2}\right\}$