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.\" @(#)isinf.3 8.2 (Berkeley) 1/29/94
.\"
.TH ISINF 3 "15 September 1997" GNO "Library Routines"
.SH NAME
.BR isinf ,
.BR isnan
\- test for infinity or not-a-number
.SH SYNOPSIS
#include
.sp 1
int
.BR isinf (extended);
.br
int
.BR isnan (extended);
.SH DESCRIPTION
The
.BR isinf
function
returns 1 if the number is
.IR "+/- Infinity" ,
otherwise 0.
.LP
The
.BR isnan
function
returns 1 if the number is
.IR not-a-number " (NaN),"
otherwise 0.
.SH SEE ALSO
.BR math (3),
.sp 1
.IR "IEEE Standard for Binary Floating-Point Arithmetic" ,
ANSI Std 754-1985
.sp 1
.IR "Apple Numerics Manual " "(SANE)"
.SH 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.