1ISNAN(P)                   POSIX Programmer's Manual                  ISNAN(P)
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NAME

6       isnan - test for a NaN
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SYNOPSIS

9       #include <math.h>
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11       int isnan(real-floating x);
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DESCRIPTION

15       The  isnan() macro shall determine whether its argument value is a NaN.
16       First, an argument represented in a format wider than its semantic type
17       is  converted  to its semantic type. Then determination is based on the
18       type of the argument.
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RETURN VALUE

21       The isnan() macro shall return a non-zero value  if  and  only  if  its
22       argument has a NaN value.
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ERRORS

25       No errors are defined.
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27       The following sections are informative.
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EXAMPLES

30       None.
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APPLICATION USAGE

33       None.
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RATIONALE

36       None.
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FUTURE DIRECTIONS

39       None.
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SEE ALSO

42       fpclassify() , isfinite() , isinf() , isnormal() , signbit() , the Base
43       Definitions volume of IEEE Std 1003.1-2001, <math.h>
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46       Portions of this text are reprinted and reproduced in  electronic  form
47       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
48       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
49       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
50       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
51       event of any discrepancy between this version and the original IEEE and
52       The Open Group Standard, the original IEEE and The Open Group  Standard
53       is  the  referee document. The original Standard can be obtained online
54       at http://www.opengroup.org/unix/online.html .
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58IEEE/The Open Group                  2003                             ISNAN(P)
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