Returns a Not-a-Number (NaN).
[Classification]
Mathematical library
[Syntax]
#include <math.h>
long double __far nanl(const char __far *tagp); (C99)
[Return value]
Returns a Not-a-Number (NaN).
[Description]
This function is equivalent to strtold("NAN(n character string)", (char __near * __near *)NULL).