ISINF(3)                    BSD Programmer's Manual                   ISINF(3)

NAME
     isinf, isnan - test for infinity or not-a-number (NaN)

SYNOPSIS
     int
     isinf(double)

     int
     isnan(double)

DESCRIPTION
     The isninf() function returns 1 if the number is ``infinity'', otherwise
     0.

     The isnan() function returns 1 if the number is ``NaN'', otherwise 0.

SEE ALSO
     math(3)

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

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.

BSDI BSD/386                    March 26, 1993                               1