Suppressed correlative 

The logical fallacy of suppressed correlative is a type of argument which tries to redefine a correlative (two mutually exclusive options) so that one alternative encompasses the other, i.e. making one alternative impossible.

Examples:

Actor 1: "Ants are not small because they are larger than bacteria."
Actor 2: "However, bacteria are also small."
Actor 1: "No, bacteria are larger than viruses. Everything is larger than something, so nothing is really small."

This type of fallacy is often used in conjunction with one of the fallacies of definition.

See also