On Keynes's Z-function

This paper is intended to give a general, but rigorous view about what is the Z-function and what are the hidden relations of the Keynes’s General Theory. In Section 1 I shall depict the concept of probability and that of the weight of argument, in Section 2 I shall introduce quite an important definitions such as the Z-function is different from the Z∗-curve, and some paramount notions. The Section 4 is intended to grasp the importance of the chapters 20-21 of the General Theory, whereas in Section 5 I shall comment, very quickly, some properties of Z∗ in a topological view.