Newsgroups: comp.constraints
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From: thom@ecrc.de (Thom Fruehwirth)
Subject: Re: Turning a n-ary constraint graph into a bina
Message-ID: <DHEuwp.GC7@ecrc.de>
Sender: news@ecrc.de
Reply-To: thom@ecrc.de
Organization: European Computer-Industry Research Centre GmbH.
References: <477kmg$gb@nic.wi.leidenuniv.nl>
Date: Thu, 2 Nov 1995 10:10:01 GMT
Lines: 25

rekers@wi.leidenuniv.nl (Jan Rekers) wrote on 1 Nov 1995 11:12:15 GMT:

	Could some kind person explain me what collection of binary
	onstraints would for example be equivalent to the following ternary
	constraint?

  	I have three integer variables X, Y and Z and have the constraint
  	X+Y = Z.


---
Ok, this is difficult since the domain is infinite. 
Assume positive integers.

Assume I is the result of taking the squareroot of N and rounding
it downwards in the following binary constraints:

add(N,X) if X=N-I and X>=0
add(N,Y) if Y=2*I-N and Y>=0
add(N,Z) if Z=I

---
thom
http://www.ecrc.de/staff/thom/

