Return to the standard-form LP of Exercise 6-33(a).

(a) Solve the model by Dual Simplex Algorithm 6A starting from the all surplus basis (x3, x4). At each step, identify the basis matrix B, its inverse B-1, the corresponding primal solution x, the basic cost vector cB, the corresponding dual solution v, reduced costs on all primal variables, direction of change  v, and step size l. Also verify (i) each v is dual feasible in your dual of 6-33(c), (ii) each v and x together satisfy complementary slackness 6-33(d), and (iii) each is improving for the dual.

(b) Track your progress with Algorithm 6A on an (x1, x2) plot of the original LP, and comment.