Newsgroups: comp.lang.prolog
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From: alan@geg.mot.com (Alan Newman)
Subject: Re: prolog syntax
Organization: /u2/newman/.organization
Date: 30 Sep 94 15:53:24
Message-ID: <NEWMAN.94Sep30155324@cujo.schbbs>
In-Reply-To: 31mangla@wmich.edu's message of 28 Sep 94 22:18:58 EDT
References: <1994Sep28.221859.21888@wmichgw>
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In article <1994Sep28.221859.21888@wmichgw> 31mangla@wmich.edu (Usman A. Mangla) writes:
   This may be a stupid question, but if you define a fact, it becomes true.
   How can you make it false.

   example:

   sunny.
   warm.
   nice:- sunny, warm.
   ?-nice.
     yes

   Can I now say it is not sunny?  

?- retract(sunny).
yes
?- nice.
no

(Congratulations, this newsgroup only answers 1 homework problem/semester. :-)
