Abstract. This paper is an extension of a previous work where two nondeterminism analyses were presented. One of them was efficient but not very powerful and the other one was more powerful but very expensive. Here, we develop an intermediate analysis in both aspects, efficiency and power. The improvement in efficiency is obtained by speeding up the fixpoint calculation by means of a widening operator, and the representation of functions through easily comparable signatures. Also details about the implementation and its cost are given.