Anchor: A move from offering no presort program to offering a discount greater than 4.5a, then, is not Pareto optimal.
Entailed: It is not optimal to move from that program.
Contradiction: They should move from the presort program.
Contradiction: A man is playing black jack.
Contradiction: There are windmills in Cape San Antonio.
Contradiction: The usps refused to give discounts or negotiate. 
Contradiction: The dog plays outside.