ISINF(3)                       Library Routines                       ISINF(3)

NAME

       isinf, isnan - test for infinity or not-a-number

SYNOPSIS

       #include <math.h>

       int isinf(extended);
       int isnan(extended);

DESCRIPTION

       The  isinf  function returns 1 if the number is +/- Infinity, otherwise
       0.

       The isnan function returns 1 if the number is not-a-number (NaN),  oth‐
       erwise 0.

SEE ALSO

       math(3),

       IEEE Standard for Binary Floating-Point Arithmetic, ANSI Std 754-1985

       Apple Numerics Manual (SANE)

BUGS

       Neither  the VAX nor the Tahoe floating point have distinguished values
       for either infinity or not-a-number.  These routines always return 0 on
       those architectures.



GNO                            15 September 1997                      ISINF(3)