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Re: is the < operator transitive?

From James Kuyper <jameskuyper@verizon.net>
Newsgroups comp.lang.c
Subject Re: is the < operator transitive?
Date 2011-10-07 21:38 -0400
Organization A noiseless patient Spider
Message-ID <j6o9ji$dnh$1@dont-email.me> (permalink)
References <4e8f3298$0$23280$426a74cc@news.free.fr> <4E8F54C9.5080009@verizon.net> <j6o3rt$g84$1@dont-email.me>

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On 10/07/2011 08:00 PM, Eric Sosman wrote:
> On 10/7/2011 3:36 PM, James Kuyper wrote:
>> On 10/07/2011 01:10 PM, Francois Grieu wrote:
>>> Is it certain that  ( a<b&&  b<c&&  !(a<c) )  is 0?
>>
>> No.
>>
>>> First assume that each of  a b c  is a constant
>>> per ISO/IEC 9899:1999 6.4.4 ?
>>
>> None of the counterexamples  that I was able to come up with could be
>> demonstrated using constants, since C constants cannot be negative (-1
>> is a unary expression, not a constant),[...]
> 
>      Nitpick:
> 
> 	enum { MINUSONE = -1 };
> 
> Now MINUSONE *is* an `int' constant with negative value, hence
> 
> 	(MINUSONE < 0 && 0 < 1u && !(MINUSONE < 1u))
> 
> evaluates to 1.

You're right, I missed that - so it is possible to demonstrate that '<'
isn't necessarily transitive just using constants:

	(98765UL < MINUSONE ) && ( MINUSONE < 1) && !(97865UL < 1)
-- 
James Kuyper

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Thread

is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-07 19:10 +0200
  Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-07 13:44 -0500
  Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 18:50 +0000
    Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 12:42 -0700
      Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 20:23 +0000
        Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 14:29 -0700
        Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 16:49 -0700
          Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 19:19 -0700
        Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-08 09:57 -0400
    Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 13:17 +0100
      Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-08 06:06 -0700
        Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 14:48 +0100
          Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-08 07:18 -0700
          Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-08 15:19 +0100
  Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 18:50 +0000
    Re: is the < operator transitive? jacob navia <jacob@spamsink.net> - 2011-10-07 21:23 +0200
      Re: is the < operator transitive? Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2011-10-07 20:24 +0000
        Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 16:40 -0400
          Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 23:12 +0100
            Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-07 15:28 -0700
              Re: is the < operator transitive? Harald van Dijk <truedfx@gmail.com> - 2011-10-07 15:31 -0700
              Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 23:36 +0100
                Re: is the < operator transitive? Patrick Scheible <kkt@zipcon.net> - 2011-10-07 16:18 -0700
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 10:32 +0100
            Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 18:30 -0400
              Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 00:21 +0100
                Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 21:33 -0400
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 10:45 +0100
                Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 14:02 -0400
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 21:49 +0100
                Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 17:17 -0400
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 22:59 +0100
                Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-08 21:33 -0400
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-09 09:09 +0100
                Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-09 07:00 -0400
                Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-09 01:12 +0100
                Re: is the < operator transitive? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-09 08:55 +0100
            Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-07 18:16 -0500
              Re: is the < operator transitive? David Thompson <dave.thompson2@verizon.net> - 2011-10-18 02:03 -0400
                Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-20 18:03 -0500
        Re: is the < operator transitive? Keith Thompson <kst-u@mib.org> - 2011-10-07 16:50 -0700
    Re: is the < operator transitive? "io_x" <a@b.c.invalid> - 2011-10-09 11:00 +0200
      Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 09:42 +0000
        Re: is the < operator transitive? Ike Naar <ike@sverige.freeshell.org> - 2011-10-09 12:20 +0000
          Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 12:40 +0000
            Re: is the < operator transitive? Ike Naar <ike@sverige.freeshell.org> - 2011-10-09 12:54 +0000
              Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 13:04 +0000
            Re: is the < operator transitive? "BartC" <bc@freeuk.com> - 2011-10-09 15:34 +0100
              Re: is the < operator transitive? Willem <willem@toad.stack.nl> - 2011-10-09 15:08 +0000
            Re: is the < operator transitive? Robert Wessel <robertwessel2@yahoo.com> - 2011-10-09 12:14 -0500
  Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 15:36 -0400
    Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-07 20:00 -0400
      Re: is the < operator transitive? James Kuyper <jameskuyper@verizon.net> - 2011-10-07 21:38 -0400
      Re: is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-09 21:40 +0200
        Re: is the < operator transitive? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-09 16:34 -0400
          Re: is the < operator transitive? Francois Grieu <fgrieu@gmail.com> - 2011-10-11 14:08 +0200
          Re: is the < operator transitive? Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 16:14 -0800

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