Ehrig, Hartmut; Rosen, Barry K. Commutativity of independent transformations on complex objects. (English) Zbl 0355.68053 IBM Research Rep., RC 6251, 52p. (1976). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 1 ReviewCited in 2 Documents MSC: 68Q45 Formal languages and automata 05C30 Enumeration in graph theory PDF BibTeX XML