[PPL-devel] [Fwd: Re: Any Prolog language lawyer out there?]

[Roberto Bagnara]

-------- Original Message --------
Subject: Re: Any Prolog language lawyer out there?
Date: Wed, 20 Oct 2004 10:12:00 +0200
From: Bart Demoen <bmd at cs.kuleuven.ac.be>
Organization: KULeuvenNet
Newsgroups: comp.lang.prolog
References: <41750912.8040102 at cs.unipr.it> <1098196164.417498 at seven.kulnet.kuleuven.ac.be> <slrncnaat8.jkn.jan at ct.xs4all.nl> <87acuijutl.fsf at gondolin.bb.bawue.de>

Jens Kilian wrote:

> This explicitly codifies the interpretation of '- 4' seen above.



http://www.sju.edu/~jhodgson/prolog_proj/framed_spec.html
has an executable ISO Prolog. One can submit goals and it
tells you the result. Here are some examples related to -4:
(I have removed some noise from the output)


Goal     : integer(- 4)
Specification result :     Must fail



Goal     : integer(-4)
Specification result :     Must succeed


So it seems that the space between the - and the 4 is important.

I do not have the final copy of the standard, and although I do remember
that there has been discussion about it, I do not remember the final outcome,
so can anybody check that's indeed what the standard says ?

Cheers

Bart Demoen

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it