Learn English – Contrapositive and Contranegative

meaning

What do contrapositive and contranegative mean and when are these used with respect to positive and/or negative?

I specifically have this article in mind. The word contranegative is used in the fourth paragraph.

Best Answer

From contraposition

Contraposition is a logical relationship between two propositions, or statements. For example, take the following (true) proposition: "All bats are mammals." We can restate that as "If something is a bat, then it is a mammal." The contrapositive is, "If something is not a mammal, then it is not a bat."

I assume the reverse apply to contranegative.