Linguistic glob

Mathematical Symbols: How the human language is created. Creating the mathematical symbols is the point where the human spoken language started. I wrote spoken language, not written language. Human language is based on mathematical-geometrical symbols. For example, the number one symbol is not just number one but it is also, one of the its directions, it is the concept of "simple" on it, not complicated because it is just a line. And they created the word "simple" only saying "as I is" , or ""I" is", combining with the other mathematical-geometrical symbols they created before. And there are more linguistic-mathematics direction on that symbol.   When they put two lines together to "y" symbol they created at the same time the number 2 concept and the number 2 word. So, the primitive number 2 was just an "y". Later they created more adding more mathematical concepts like "T", not this "T" but Etrus

Is the Actual Mating Envelope and Datum mean the same thing for this Feature of Size (10 mm Pin) ? No. they are different concepts. The datum is a theoretical surface (perfect points, lines, and planes). Measurements cannot be made from theoretical surfaces. It is the perfect cylinder of the pin, theoretical. The purpose of datumes is for the location and orientation of features, it is the origin from which the location or geometric characteristics of features of a part are established The mating envelope of the 10 mm pin, that happened to be also a datum, is not a theoretical surface. The diameter of this perfect cylinder can get bigger or smaller as required, and more ever is not the size of the pin but the size of the smallest hole in which the actual pin size goes in. So, it is an actual size, not a theoretical one. The actual mating envelope of a pin is the smallest similar hole counterpart that fits over the pin and contacts the pin at the highest points.  There a