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Re: How the computer identify an NaN?

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On 15-Aug-11 23:45, fl wrote:
> If NaN won't equal to anything, any number will not equal to itself
> either.

Incorrect.

A number is always equal to itself.  However, a NaN is Not a Number, and
the rules are different from numbers: it never compares equal to itself.

> I still do not understand b_u != b_u;
> 
> ex:
> b_u = 3;
> (b_u!=b_u) ==> 1, right?

Since 3 is a number, (3 != 3) is false.  That condition would only be
true for NaNs, which are not numbers.

S

-- 
Stephen Sprunk         "God does not play dice."  --Albert Einstein
CCIE #3723         "God is an inveterate gambler, and He throws the
K5SSS        dice at every possible opportunity." --Stephen Hawking

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Thread

How the computer identify an NaN? fl <rxjwg98@gmail.com> - 2011-08-15 20:19 -0700
  Re: How the computer identify an NaN? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-16 04:33 +0100
    Re: How the computer identify an NaN? fl <rxjwg98@gmail.com> - 2011-08-15 21:45 -0700
      Re: How the computer identify an NaN? Robert Wessel <robertwessel2@yahoo.com> - 2011-08-16 00:45 -0500
      Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 08:51 +0200
        Re: How the computer identify an NaN? bert <bert.hutchings@btinternet.com> - 2011-08-16 02:01 -0700
          Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 13:04 +0200
            Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:28 +0000
              Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:31 +0000
                Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 14:08 +0200
              Re: How the computer identify an NaN? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-16 13:37 +0100
                Re: How the computer identify an NaN? jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 21:13 +0000
            Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 14:17 +0200
          Re: How the computer identify an NaN? "Heinrich Wolf" <invalid@invalid.invalid> - 2011-08-16 13:22 +0200
            Re: How the computer identify an NaN? Angel <angel+news@spamcop.net> - 2011-08-16 15:17 +0000
      Re: How the computer identify an NaN? James Kuyper <jameskuyper@verizon.net> - 2011-08-16 08:42 -0400
      Re: How the computer identify an NaN? Stephen Sprunk <stephen@sprunk.org> - 2011-08-16 09:25 -0500
      Re: How the computer identify an NaN? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-08-16 12:37 -0600
        Re: How the computer identify an NaN? Keith Thompson <kst-u@mib.org> - 2011-08-16 12:26 -0700

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