# Proper Subset Relation

A Proper Subset Relation is a Subset Relation that is False If *X*_{1}≡*X*_{2}.

**AKA:**Proper Subset, ⊂, ProperSubset, Proper Subset Operation.**Example(s):**- {1, 2} ⊂ {1, 2, 3}.
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**Counter-Example(s):**- {1, 2, 3} ⊆ {1, 2, 3}.

**See:**Subset Operation, Intersection Set Operation, Set Equivalence Relation.