studies on combina- torics is very meagre. Leibniz himself spoke of the ?ars
combinatoria?, a philosophical term to which he attached differ- ent meanings in
the course of his life, but which always embraced more than what we call .... by
Marin Mersenne [1635, 135 ff.;. 1636, Livre des Chants, 134; see Knobloch
19741. 
