U+21CE "⇎" Left Right Double Arrow with Stroke Unicode Character

U+21CE "⇎" Left Right Double Arrow with Stroke is a mathematical symbol used primarily in logic and mathematics to denote the "not equivalent" relation, representing the negation of a bidirectional logical equivalence. It combines a left-right double arrow with a diagonal stroke through its center, visually indicating that two statements or values are not mutually implied. This character is part of the Arrows block in Unicode and is commonly employed in formal proofs, set theory, and computer science contexts to express inequality or the failure of a biconditional relationship.