\SubsetThe symbol \Subset is used to denote a subset relation in set theory, specifically indicating that one set is a subset of another set, but not necessarily equal to it. It is a strict subset relation, meaning that the subset does not contain all elements of the other set.
Set A is a strict subset of set B, meaning all elements of A are in B, but A is not equal to B.
A \Subset BThe set containing elements 1 and 2 is a strict subset of the set containing elements 1, 2, and 3.
\{1, 2\} \Subset \{1, 2, 3\}If X is a strict subset of Y, then X is not equal to Y.
X \Subset Y \Rightarrow X \neq Y