Given two sets and , we say that is a subset of (which we denote as or simply ) if every element of is also in . That is, the following implication holds:
The set is a subset of the set because every element of is also in . That is, .
On the other hand, if , then neither (because but ) nor (because but ). The fact that is not a subset of is written as . Similarly, we have .
If and , it must be the case that .
|Date of creation||2013-03-22 11:52:38|
|Last modified on||2013-03-22 11:52:38|
|Last modified by||Wkbj79 (1863)|