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From: pereira@alice.att.com (Fernando Pereira)
Newsgroups: comp.lang.prolog
Subject: Re: origin of "arity"
Message-ID: <20442@alice.att.com>
Date: 23 Jun 91 04:20:02 GMT
References: <3405@shodha.enet.dec.com> <6402@goanna.cs.rmit.oz.au>
Reply-To: pereira@alice.UUCP ()
Organization: AT&T, Bell Labs
Lines: 22

In article <6402@goanna.cs.rmit.oz.au> ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:
>In article <3405@shodha.enet.dec.com>, wahl@shodha.enet.dec.com (David Wahl) writes:
>> The word "arity" came up during lunch today in our group and our
>> resident mathematician asked whether the word was invented by
>> logic programming people or whether it was borrowed from another
>> field.
>Neither ``arity'' nor ``functor'' was invented by logic programmers.
>You can find ``functor'' in Robinson's book.
>
> [various references]

Richard's references are relatively recent. I first encountered the term 
in books on universal algebra, eg. P. M. Cohn's ``Universal Algebra'' (1965).
Mac Lane's ``Categories for the Working Mathematician'' (1971) uses it too.
This in just a quick survey of my home library.

Fernando Pereira
AT&T Bell Laboratories, Murray Hill
pereira@research.att.com