anchor: For example, suppose the discount is 4a (per piece) and the mailer's cost of doing the work is 3.8a.
positive: Suppose the mailer's cost of doing the work is 3.8a, and the discount is 4a (per piece), for example.
negative: For example, suppose the discount is 41z, and the mailer's cost of doing the work is 91.4x.