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Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!ihnp4!inuxc!pur-ee!uiucdcs!ctvax!paul
From: paul@ctvax.UUCP
Newsgroups: net.ai
Subject: Re: OPS5 disjuction dilemma.
Message-ID: <45200004@ctvax.UUCP>
Date: Thu, 15-Nov-84 13:25:00 EST
Article-I.D.: ctvax.45200004
Posted: Thu Nov 15 13:25:00 1984
Date-Received: Tue, 20-Nov-84 23:45:29 EST
References: <10900006@smu.UUCP>
Lines: 28
Nf-ID: #R:smu:10900006:ctvax:45200004:000:642
Nf-From: ctvax!paul    Nov 15 12:25:00 1984

The solution is simple (though a little ugly). Productions themselves
are disjunctions. The idea is that rules be aranged into disjunctive
form, then each disjunction is a separate OPS5-rule. and each rule
is itself a conjunction (with possible negations).

(p variant1
   ...ce's that bind <foo1> and <foo2> ...
   ( <foo1> <foo2> )
   -->
   (make found))

(p variant2
   ...ce's that bind <foo1> and <foo2> ...
   ( <foo2> <foo1> )
   -->
   (make found))

(p var1orvar2
   ...ce's that bind <foo1> and <foo2> ...
   (found)
   -->
   .... rhs goes here ...)

This way you can avoid duplication of the RHS.

paul.ct@CSNet-Relay
ctvax!paul