where I have replaced \(\displaystyle P\) by \(\displaystyle B'\), \(\displaystyle Q\) by \(\displaystyle \oslash\) and \(\displaystyle R\) by \(\displaystyle A'\).

where I have replaced \(\displaystyle P\) by \(\displaystyle B'\), \(\displaystyle Q\) by \(\displaystyle \oslash\) and \(\displaystyle R\) by \(\displaystyle A'\).

Yes, I'm rather afraid that you do. As I said - you'll need lots of practice!

Grandad

PS ... and to answer your extra question, following your edit:

\(\displaystyle \oslash \cap A' = \oslash\) uses what I have always known as an Identity Law, but others sometimes refer to as a Domination Law.