Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #11339

Re: is the < operator transitive?

From Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com>
Newsgroups comp.lang.c
Subject Re: is the < operator transitive?
Date 2011-10-07 18:50 +0000
Organization Aioe.org NNTP Server
Message-ID <j6nhm0$sh9$1@speranza.aioe.org> (permalink)
References <4e8f3298$0$23280$426a74cc@news.free.fr>

Show all headers | View raw

Francois Grieu wrote:
> Is it certain that  ( a<b && b<c && !(a<c) )  is 0?
> 
> First assume that each of  a b c  is a constant per ISO/IEC 9899:1999
> 6.4.4 ?
> 
> If not, what about a counterexample?
> 
> How far can we extend (or shrink) the kind of things that  a b c  can be
> for this to hold?
> 
> In particular, what about unitialized variable such as
> 
> int foo(void) {
>    {
>    unsigned a,b,c;
>    return a<b && b<c && !(a<c);
>    }
> 
> What if unsigned is changed to int? To double?
> 
> 
>    Francois Grieu

Python comparisons have the cool feature, that a<b<c is the same as (a<b 
&& b<c). So you can use normal notation for multiple comparisons.

IMO it would be great if this could be backported to C.

// EPR

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

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

csiph-web