equivalence

[ ih-kwiv-uh-luh ns or for 3, ee-kwuh-vey-luh ns ]
/ ɪˈkwɪv ə ləns or for 3, ˌi kwəˈveɪ ləns /

noun Also equivalency (for defs 1, 2).

the state or fact of being equivalent; equality in value, force, significance, etc.
an instance of this; an equivalent.
Chemistry. the quality of having equal valence.
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

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

Origin of equivalence

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

OTHER WORDS FROM equivalence

non·e·quiv·a·lence, noun

Words nearby equivalence

equity security, equity stock, equity weighting, equity-linked policy, equiv., equivalence, equivalence class, equivalence principle, equivalence relation, equivalency, equivalent

British Dictionary definitions for nonequivalence (1 of 2)

nonequivalence
/ (ˌnɒnɪˈkwɪvələns) /

noun

the relationship of being unequal or incomparable
logic
  1. the relation between two statements only one of which can be true in any circumstances
  2. a function of two statements that takes the value true only when one but not both of its arguments is true
  3. a compound statement asserting that just one of its components is true
Abbreviation: exclusive or

British Dictionary definitions for nonequivalence (2 of 2)

equivalence

equivalency

/ (ɪˈkwɪvələns) /

noun

the state of being equivalent or interchangeable
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