ymath.h ??? IAR most recent compiler ... doesn't include it.

Howdy all,

I stumbling around in some old IAR 5.9.1  code that has a custom math.h header modified to request these files.

#include <ycheck.h>
#include <ymath.h>

I have ycheck.h, but I don't have ymath.h and don't recognize it from anywhere.

Can anyone point me to whereto find/understand this include file, especially from an earlier version.