Books and articles I am reading often mention the Domain analysis technique and introduce the ON and OFF points (a point on or off the boundary). E.g. X>100, 100 is ON (and out), 101 is OFF and IN. But as with the example I just stated, isn't it also true for simple boundary value analysis? I do not think I need a domain (e.g. X>100 and Y<50) to use. Or am I missing something?