bi-conditional

A bi-conditional is a logical statement that connects two ideas, saying that each one is true if and only if the other is true. It is symbolized as "if and only if" (often written as "iff"). Essentially, it means both statements happen together—either both are true or both are false. For example, "You get a refund if and only if you return the product" means returning the product guarantees a refund, and receiving a refund only happens if you return the product. It establishes a mutual dependency between the two ideas.