The list of a set S is a list of the elements of S exactly once each, in some order.
Example:
S = {dog, 2, z}
All of the lists that can be generated from S are
dog,2,z 2,dog,z z,dog,2
dog,z,2 2,z,dog z,2,dog
A permutation is a list of the set {1, 2, ....., n} for some n belongs to N
If there is a bijection between A and B, then mod(A) = mode(B) Negative Binomial Theorem Generating series with respect to 'w’
