Symbols:Set Theory/Deprecated Symbols/Superset
$\supset$ is sometimes used to mean:
- $S$ is a superset of $T$
in the sense that $S$ is permitted to equal $T$.
That is, for which we have specified as $S \supseteq T$.
Although many sources use this interpretation, it is emphatically not recommended, as it can be the cause of considerable confusion.