Symbolic method (combinatorics): Difference between revisions

Revision as of 20:52, 8 January 2007

Revision as of 04:55, 6 March 2007

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===Examples===

Many combinatorial classes can be built using these elementary constructions. For example, the class of plane [[planetree (graph)|tree]]s (that is, trees [[embedding|embedded]] in the plane, so that the order of the subtrees matters) is specified by the [[recursion|recursive]] relation

:<math>\mathcal{G} = \mathcal{Z} \times \mathfrak{G}\{\mathcal{G}\}.</math>