Key points are not available for this paper at this time.
There are several computational problems that can be formulated as problems of counting the number of objects having a certain property. Valiant 22 has introduced the class #P which includes a variety of counting problems such as counting the number of perfect matchings in a graph, computing the permanent of a matrix 22, finding the size of a backtrack search tree 14, and computing the probability that a network remains connected when links can fail with a certain probability 23.
Larry Stockmeyer (Sat,) studied this question.