A semigroup and Gaussian polynomials
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Words are defined to be sequences @x: Z">="0 -> Z">"0 @? [~] with @x(n) = ~ for almost all n. I(@x) denotes the number of inversions in @x; i.e., the number of pairs (m, n) with m@x(n). The product, @x * @z, is defined to be a ''meshed juxtaposition'' of @x with the word @z' = @z + maximum integer in @x. (Terms of @z' are meshed into the spaces '~' in @x). With these definitions words form a unique factorization (hence cancellative) semigroup, and I(@x * @z) = I(@x) + I(@z). This is used in conjunction with Netto-MacMahon type generating functions, @?"@?"@e"A@g^I^(^@?^) to give a purely combinatorial treatment of the Gaussian polynomials. Factorization theorems and Chu-Vandermonde and Euler identities are proved.
[1] Ronald C. Read,et al. Graph theory and computing , 1972 .
[2] G. Rota,et al. On the Foundations of Combinatorial Theory IV Finite Vector Spaces and Eulerian Generating Functions , 1970 .
[3] G. Andrews. The Theory of Partitions: Frontmatter , 1976 .
[4] G. Lallement. Semigroups and combinatorial applications , 1979 .