Maths, Functionx, Mathematics, Mathematics Education, Discrete Mathematics.
choosing n items from a k­ element set {a1, a2, . . . , ak}: Convolution Rule : Let A(x) and B(x) be the generating functions for selecting items from set A and set B, respectively. If A and B are disjoint, then the generating function for selecting items from the union A ∪ B is the product( A(x) ·