מיכאל פייר

A classical result of MacMahon shows that the length function and the major index are equi-distributed over the symmetric groups. Through the years this result was generalized in various ways to signed permutation groups. In this paper we present several new generalizations, in particular, we study the effect of different linear orders on the letters [-n, n] and generalize a classical result of Foata and Zeilberger.