is also common, especially when is a transfinite cardinal number.

Other properties of inclusion

* A set A is a subset of B if and only if their intersection is equal to A. Formally:
:
* A set A is a subset of B if and only if their union is equal to B. Formally:
:
* A finite set A is a subset of B, if and only if the cardinality

1.Previous
3.Next