What is unitary counting?

Answer 1

Unitary counting is a method used in combinatorics to count the number of ways to arrange or select objects where the order does not matter, and each arrangement is considered unique. This approach often involves the use of generating functions or the principle of inclusion-exclusion. It simplifies the counting process by focusing on the distinct configurations of the objects rather than their individual permutations. Unitary counting is particularly useful in problems involving multisets or when accounting for symmetries.