I am reading Probability by A. N. Shiryaev.
- One of the problems refers to "inclusion-exclusion formulas", also known as Poincaré’s formulas, Poincaré’s theorems, Poincaré’s identities.
- One of my college textbooks refers to the formula as Jordan’s formula.
I can't find any material on the naming of the formula from Wikipedia or Wolfram. My question is, do these two aliases truly exist?