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From: vraemdon@psws.uia.ac.be (Thierry.VanRaemdonck)
Subject: Arithmetics
Message-ID: <1995Mar25.223100.19370@reks.uia.ac.be>
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Date: Sat, 25 Mar 1995 22:31:00 GMT
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Hello everybody!
I'm a student at the University of Antwerp, Belgium, Actually I'm working with version V2.32 of Prolog-2, distributed buy Exepert Systems in Oxford.
I would like to run a program which is discussed in the book Intelligent system iness: expert systems with neural networks, written by FATEMEH Zahedi and published by Wadsworth inc, Belmont, California (1993).

The program concerns a loan demand andhas a line like:
decision(X,approve):- credit(X,good), >(ratio,1.5),
assets(X,some),job(X,steady).

When I write this line in version V2.32 of Prolog-2, I get an error message because of the use of ">ratio,1.5)": Error goal: System predicates cannot be asserted, read or retracted.

Could anybody please tell me how I can avoid this error? I am sure it must be possible to use a clause like this in this version of Prolog.
Thanks in advance.
Thierry Van Raemdonck
 
