Tree calculus for bivariate difference equations.

Following Poupard's study of strictly ordered binary trees with respect to two parameters, namely, ‘end of minimal chain’ and ‘parent of maximum leaf’ a true tree calculus is being developed to solve a partial difference equation system and then make a joint study of those two statistics. Their joint distribution is shown to be symmetric and to be expressed in the form of an explicit three-variable generating function. [ABSTRACT FROM PUBLISHER]