Definition:Swelled Class

Definition
Let $A$ denote a class.

Then $A$ is a swelled class every subclass of every element of $A$ is also an element of $A$.

That is, $A$ is swelled :


 * $\forall x: \forall y: \paren {x \subseteq y \land y \in A \implies x \in A}$

Also see

 * Definition:Transitive Class
 * Definition:Supercomplete Class