What is the cornerstone of mathematics? How to calculate? Or is stepping stone just a coincidence, not counting? For example, N below FV is waste.
It's just a symbol, and it doesn't need calculation. For example, if 2 is marked with 3, it means that 2 is artificially marked with 3, and the lower corner is n, that is, there are n such people as labels, just to distinguish them. For example, there are 1, 2,, n brakes, which are just artificial labels and unnecessary.