SYNOPSIS
       #include <math.h>

       double fdim(double x, double y);
       float fdimf(float x, float y);
       long double fdiml(long double x, long double y);

       Link with -lm.

   feature test macro requirements for glibc (see feature_test_macros(7)):

       fdimf(), fdiml(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or
       cc -std=c99

DESCRIPTION
       These functions return the  positive  difference,  max(x-y,0),  between
       their arguments.

RETURN VALUE
       On success, these functions return the positive difference.

       If x or y is a NaN, a NaN is returned.

       If the result overflows, a range error occurs, and the functions return
       HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively.

ERRORS
       see math_error(7) for information on how to determine whether an  error
       has occurred when calling these functions.

       The following errors can occur:

       Range error: result overflow
              An overflow floating-point exception (FE_OVERFLOW) is raised.

       These functions do not set errno.

VERSIONS
       These functions first appeared in glibc in version 2.1.

CONFORMING TO
       C99, POSIX.1-2001.

SEE ALSO
       fmax(3)

COLOPHON
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