>SVR4 and other systems provide a header file named "nan.h" which defines
>macros and constants such that an application can determine if a given
>floating point number is NaN (not a number).  NetBSD lacks this file, but
>I am trying to port an application which uses one of its defined macros,
>namely ``IsNANorINF()''.  (Returns true if the supplied argument is NaN or
>infinity.)
>
>What the correct way to do the above in NetBSD?

$ man -k isnan
isinf, isnan (3) - test for infinity or not-a-number
$