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       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       islessgreater — test if x is less than or greater than y

SYNOPSIS

       #include <math.h>

       int islessgreater(real-floating x, real-floating y);

DESCRIPTION

       The functionality described on this reference page is aligned with the ISO C standard. Any
       conflict between the requirements described here and the ISO C standard is  unintentional.
       This volume of POSIX.1‐2017 defers to the ISO C standard.

       The  islessgreater()  macro  shall  determine  whether  its first argument is less than or
       greater  than  its  second  argument.  The  islessgreater(x,  y)  macro  is   similar   to
       (x) < (y) || (x) > (y); however, islessgreater(x, y) shall not raise the invalid floating-
       point exception when x and y are unordered (nor shall it evaluate x and y twice).

RETURN VALUE

       Upon  successful  completion,  the  islessgreater()  macro  shall  return  the  value   of
       (x) < (y) || (x) > (y).

       If x or y is NaN, 0 shall be returned.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The relational and equality operators support the usual mathematical relationships between
       numeric values. For any ordered pair of numeric values, exactly one of  the  relationships
       (less,  greater,  and equal) is true. Relational operators may raise the invalid floating-
       point exception when argument values are NaNs. For a NaN and a numeric value, or  for  two
       NaNs,  just  the unordered relationship is true. This macro is a quiet (non-floating-point
       exception raising) version of a relational operator. It facilitates writing efficient code
       that  accounts  for  NaNs  without  suffering the invalid floating-point exception. In the
       SYNOPSIS section, real-floating indicates that the argument  shall  be  an  expression  of
       real-floating type.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       isgreater(), isgreaterequal(), isless(), islessequal(), isunordered()

       The Base Definitions volume of POSIX.1‐2017, <math.h>

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by
       the Institute of Electrical and Electronics Engineers, Inc and The  Open  Group.   In  the
       event  of  any  discrepancy  between this version and the original IEEE and The Open Group
       Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .