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From: markg@aisb.ed.ac.uk (Mark Gallagher)
Subject: Re: sicstus question [not equal]
Message-ID: <CxyzJH.Ms7@aisb.ed.ac.uk>
Sender: news@aisb.ed.ac.uk (Network News Administrator)
Reply-To: markg@aisb.ed.ac.uk (Mark Gallagher)
Organization: Dept of AI, University of Edinburgh, Scotland
References: <zanikos.782253823@sfu.ca> <37t713$phc@goanna.cs.rmit.oz.au>
Date: Thu, 20 Oct 1994 11:50:04 GMT
Lines: 24

In article <37t713$phc@goanna.cs.rmit.oz.au>, ok@goanna.cs.rmit.oz.au (Richard
A. O'Keefe) writes:
# zanikos@gemini.csil.sfu.ca (Dimitrios Zanikos) writes:
# 
# >Hi, does anyone know the symbol(s) for 'does not equal' in sicstus?
# >In another language such as pascal it would be '<>' ..
# 
# In Fortran, it is .NE.
# In C, it is !=
# In Burroughs Algol, it was ~=
# In Haskell, it's /=
# Pascal is the _only_ programming language I've ever met where inequality
# is written <>, and it was a particularly unfortunate choice because
 
 It's used in some BASIC interpreters, notably BBC BASIC.

#  - in complex arithmetic (part of the current Pascal standard), there
#    is no < or > to which inequality might be related
#  - given two sets A and B, A <> B might be true, but A < B (proper subset)
#    and A < B (proper superset) might both be false
#  - in IEEE floating-point arithmetic, it is possible for x ~= y to be true,
#    and for x < y and x > y both to be false.

   [etc.]
