Noun

(uncountable) Oneness; the state or fact of being one undivided entity.

* 1846 ,

If any literary work is too long to be read at one sitting, we must be content to dispense with the immensely important effect derivable from unity of impression - for, if two sittings be required, the affairs of the world interfere, and everything like totality is at once destroyed.

* {{quote-news

, year=2011 , date=October 1 , author=Saj Chowdhury , title=Wolverhampton 1 - 2 Newcastle , work=BBC Sport citation , page= , passage=Alan Pardew's current squad has been put together with a relatively low budget but the resolve and unity within the team is priceless.}}

A single undivided thing, seen as complete in itself.

* 1999 , Joyce Crick, translating Sigmund Freud, The Interpretation of Dreams , Oxford 2008, p. 137:

If a single day has brought us two or more experiences suitable to initiate a dream, the dream will unite references to them both into a single whole; it obeys a compulsion to form a unity out of them .

(drama) Any of the three classical rules of drama (unity of action, unity of place, and unity of time).`

(mathematics) Any element of a set or field that behaves under a given operation as the number 1 behaves under multiplication.

(legal) The peculiar characteristics of an estate held by several in joint tenancy.

Noun

The act of unifying.

The state of being unified.

(mathematical logic, computer science) Given two terms, their join with respect to a specialisation order.

*

5.7.T ( Unification theorem' ) For any two terms or formulas
without quantifiers X and Y, the following holds.
(i) The ' unification algorithm UNIF₁, applied to X, Y,
terminates after a finite number of steps.
(ii) {X, Y} is unifiable iff UNIF₁ so indicates upon ter-
mination. Moreover, the substitution σ then available as out-
put is a most general unifier of {X, Y}.