Article View: comp.lang.prolog
Article #830Re: Does It Unify?
From: Fernando Pereira
Date: Fri, 18 May 1990 14:56
Date: Fri, 18 May 1990 14:56
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In article <40089@brunix.UUCP> mj@cs.brown.edu (Mark Johnson) writes: >It is computationally cheaper to implement safe unification and eq-tests >than to implement the occurs check. It is not clear that this is the case asymptotically , see for instance ``An Almost Linear Robinson Unification Algorithm'' by Peter Ruzicka (missing some diacritics) and Igor Privara, Acta Informatica 27, pp.61-71, 1989. Unfortunately, the real problem is constant factors; every rational term unification algorithm I know requires far more (and more complex) trailing of side-effects to terms than the usual Prolog unification. No free lunch... Fernando Pereira 2D-447, AT&T Bell Laboratories 600 Mountain Ave, Murray Hill, NJ 07974 pereira@research.att.com
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<1990May7.132305.15989@agate.berkeley.edu> <189@qt.cs.utexas.edu> <24861@pasteur.Berkeley.EDU> <191@qt.cs.utexas.edu> <10809@alice.UUCP> <194@qt.cs.utexas.edu> <40089@brunix.UUCP>Show Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uwm.edu!rpi!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!att!dptg!ulysses!andante!alice!pereira From: pereira@alice.UUCP (Fernando Pereira) Newsgroups: comp.lang.prolog Subject: Re: Does It Unify? Message-ID: <10838@alice.UUCP> Date: 18 May 90 14:56:47 GMT References: <1990May7.132305.15989@agate.berkeley.edu> <189@qt.cs.utexas.edu> <24861@pasteur.Berkeley.EDU> <191@qt.cs.utexas.edu> <10809@alice.UUCP> <194@qt.cs.utexas.edu> <40089@brunix.UUCP> Reply-To: pereira@alice.UUCP () Distribution: usa Organization: AT&T, Bell Labs Lines: 17