books.google.com - A computational model is a framework for doing computations according to certain specified rules on some input data. These models come for example from automata theory, formal language theory, logic, or circuit theory. The computational power of such a model can be judged by evaluating certain problems...http://books.google.com/books/about/The_Computational_Complexity_of_Equivale.html?id=e3xOiREJF4EC&utm_source=gb-gplus-shareThe Computational Complexity of Equivalence and Isomorphism Problems
