Two methods of estimation of Boolean bijunctive function weights

A problem of computation of the weight of function representable as 2-CNF (i. e. bijunctive function) belongs to the class of hard enumeration problems. Nevertheless there exist methods of upper and lower estimation of the weight of such functions. We consider two methods of estimation the weights: inclusionexclusion method and method using the monotone function on graph corresponding to the 2-CNF representing the bijunctive function. By means of these methods several polynomially computable estimates of the bijunctive functions weights are constructed.