equivalence

[ih-kwiv-uh-luhns, ee-kwuh-vey-luhns]

noun

1. the state or fact of being equivalent; equality in value, force, significance, etc.

2. an instance of this; an equivalent.

3. Chemistry.,  the quality of having equal valence.

4. Logic, Mathematics.

   1. Also called material implication. the relation between two propositions such that the second is not false when the first is true.

   2. Also called material equivalence. the relation between two propositions such that they are either both true or both false.

   3. the relation between two propositions such that each logically implies the other.

adjective

1. (of a logical or mathematical relationship) reflexive, symmetrical, and transitive.

equivalence

/ ɪˈkwɪvələns /

noun

1. the state of being equivalent or interchangeable

2. maths logic

   1. the relationship between two statements, each of which implies the other

   2. Also called: biconditional. the binary truth-function that takes the value true when both component sentences are true or when both are false, corresponding to English if and only if . Symbol: ≡ or ↔, as in –( p ∧ q ) ≡ – p ∨ – q

Other Word Forms

• nonequivalence noun

Word History and Origins

Origin of equivalence¹

1535–45; < Middle French < Medieval Latin aequivalentia, equivalent to Latin aequivalent- equivalent + -ia -ia; -ence