<p>It's common to say that $f$ and $g$ commute with respect to composition (where the property is known as commutativity). See, e.g., <a href="http://en.wikipedia.org/wiki/Function_composition">http://en.wikipedia.org/wiki/Function_composition</a>.</p>

CC BY-SA 3.0
2014-03-19T21:54:13.833Z
2014-03-19T21:54:13.833Z
Rahul Savani
<p>There is a <a href="http://www.ams.org/journals/tran/1923-025-03/S0002-9947-1923-1501252-3/S0002-9947-1923-1501252-3.pdf" rel="nofollow">paper by Ritt from 1923</a> that calls the relation,  $f(g(x)) = g(f(x))$, <em>permutable functions</em>. Is there a more recent terminology used in the literature, or is this still the standard?</p>

<circuit-complexity><terminology><functional-programming>
Terminology for f(g(x)) = g(f(x))
Chad Brewbaker
# Terminology for f(g(x)) = g(f(x))

(Asked by: username_0 on 2014-03-19)

There is a [paper by Ritt from 1923](http://www.ams.org/journals/tran/1923-025-03/S0002-9947-1923-1501252-3/S0002-9947-1923-1501252-3.pdf) that calls the relation, $f(g(x)) = g(f(x))$, *permutable functions*. Is there a more recent terminology used in the literature, or is this still the standard?

**Tags:** circuit-complexity, terminology, functional-programming


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## 1 answers

### Answer by username_1 on 2014-03-19. Score: 17 | Accepted answer

It's common to say that $f$ and $g$ commute with respect to composition (where the property is known as commutativity). See, e.g., <http://en.wikipedia.org/wiki/Function_composition>.


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