biconditional

noun
  1. a logical statement that is true when two propositions have the same truth value (both true or both false), typically expressed as 'if and only if'
  2. Usage: formal logic and mathematics; symbol: ↔ or ≡
adjective
  1. relating to or denoting a logical statement that connects two propositions with mutual dependence
  2. Usage: formal logic and mathematics

Examples