How can Quine McCluskey be applied for product of sum

Question

I know the algorithm of QM for SoP but I'm not sure whether for PoS I should group them by 0's or group them by 1 and in the end simply use products instead of sum.Searched for this but can't find it

Answer 1

Since (A+B)(A+B') = A, QM should work on CNF as well as DNF. I don't see that there is any difference between grouping by 0's or 1's. The only purpose of that (as far as I understand it) is to assure that mergable clauses are in adjacent groups, and nothing in the same group is mergable. I.e., no two clauses with the same number of 1s are mergable, and not two clauses with the same number of zeros is mergable.