Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!amdahl!nsc!taux01!shahaf
From: shahaf@taux01.UUCP (Shahaf Moshe)
Newsgroups: comp.lang.prolog
Subject: Re: mine embarrassingly simple problem
Message-ID: <512@taux01.UUCP>
Date: 21 Mar 88 09:26:04 GMT
References: <500@taux01.UUCP> <764@cresswell.quintus.UUCP> <503@taux01.UUCP> <13364@comp.vuw.ac.nz>
Reply-To: shahaf%taux01@nsc.COM
Organization: National Semiconductor (Israel) Ltd. Home of the 32532
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Summary:

Followup-To:

Hdate: 3 Nisan 5748


In article <13364@comp.vuw.ac.nz> lindsay@comp.vuw.ac.nz (Lindsay Groves) writes:
>I'll save Richard saying it -- this doesn't say much about the program, and 
>certainly doesn't explain why ancestral cuts are supposed to be necessary.
>Could you describe the problem in a bit more detail and illustrate just 
>how the need for ansectral cuts arises?  Perhaps a simplified version of the
>problem could be used to illustrate the point.  An example would certainly 
>help.

First I would like to make two comments:
* I am a NOVICE (in Prolog).
* I do not claim that in my application Ansectral Cut are a MUST. I wrote it on
  a system were it was a feature and I used it. Since its not available in
  Quintus Prolog, I asked for help.

About the application,
The program looks for best mapping of a Boolean function onto a set of logic
primitives such as 
	X * Y * Z maps to: 2inputAnd( 2inputAnd( X, Y) , Z)
	               or: 3inputAnd( X, Y, Z)
	       
	       Since the search space is huge I used Ansectral Cut to abort
mapping once I get some "STOP CONDITIONS".

The program looks like:

map(Function,Network) :-
			generate(Function,Network),
			test(Network).
test(Network) :-
		lemma(Network,StopCondition),
		!(map).	    %this cut aborts the process.

I hesitate to post longer description on the net. If anyone would like to
get more elaborated data I will mail upon request.

shahaf%taux01@nsc.com