Article View: comp.lang.prolog
Article #2532Re: 91 function
From: kyukawa
Date: Sun, 25 Jan 1987 01:54
Date: Sun, 25 Jan 1987 01:54
15 lines
890 bytes
890 bytes
The 91 function was cooked up by J. McCarthy and is defined as: F(x) = if x > 100 then x-10 else F(F(x+11)), whose least fixpoint is: f(x) = if x > 100 then x-10 else 91. So it doesn't always return 91. It has been used for exercises in recursive program schemata and program verification. For reference, see Mathematical Theory of Computation, by Z. Manna Chapter 5.
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!watnot!watdragon!kyukawa From: kyukawa@watdragon.UUCP Newsgroups: comp.lang.prolog Subject: Re: 91 function Message-ID: <2168@watdragon.UUCP> Date: Sat, 24-Jan-87 20:54:48 EST Article-I.D.: watdrago.2168 Posted: Sat Jan 24 20:54:48 1987 Date-Received: Sun, 25-Jan-87 05:36:33 EST Distribution: comp Organization: U of Waterloo, Ontario Lines: 15 Keywords: recursive program schemata, program verification