Koppitz, J¨org; Shtrakov, Slavcho
(ДЗ "Луганський національний університет імені Тараса Шевченка, 2005)
The extensions of hypersubstitutions are mappings on the set of all terms. In the present paper we characterize all hypersubstitutions which provide bijections on the set of all
terms. The set of all such hypersubstitutions ...