ThmDex – An index of mathematical definitions, results, and conjectures.

ThmDex – An index of mathematical definitions, results, and conjectures.

Formulation F6385 on R2615: Empty set is cofinite within a finite set

F6385

Formulation 0

Let $X$ be a D17: Finite set.
Let $\emptyset$ be the D13: Empty set.

Then $\emptyset$ is a D1880: Cofinite set within $X$.