U+2288 "⊈" Neither A Subset of nor Equal To Unicode Character

U+2288 "⊈" Neither A Subset of nor Equal To is a mathematical symbol used in set theory to indicate that one set is not a subset of another set and is also not equal to it, effectively combining a negation of two relations. It visually resembles the standard subset symbol (⊆) but with a diagonal stroke through it, signaling that the relationship it describes is false. In formal notation, "A ⊈ B" means that set A is not a subset of set B and A is not equal to B, so there exists at least one element in A that is not in B, and the sets are distinct. This symbol is commonly encountered in proofs, logic, and discrete mathematics where precise set relationships must be articulated.