I'm doing a research project that involves subdividing a product of simplices. Specifically, I'm looking at theorem 2.4 from this paper:
which references for proof:
Neither paper defines "regular subdivision" or references a definition, and other literature definitions are rare and not obviously equivalent. Can someone with more background in this field give a formal definition, and if that doesn't by itself give a reasonable intuition, some examples of regular vs. irregular subdivisions?