Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Properties of the Boolean relations
| Relation | Symmetry | Reflexivity | Transitivity |
|---|---|---|---|
| Equivalent | Symmetric | Reflexive | Transitive |
| Contains | Asymmetric | Irreflexive | Transitive |
| Is contained | Asymmetric | Irreflexive | Transitive |
| Overlap | Symmetric | Irreflexive | Intransitive |
| Disjoint | Symmetric | Irreflexive | Intransitive |
Note: The converse of ‘contains’ is ‘is contained’ and vice versa.
