A useful view is to think of all computation as simulation.
* cf.*: * Isomorphism of semigroups* [Preparata, F. P. and
Yeh, R. T., * Introduction to Discrete Structures*, Addison-Wesley, 1973,
p. 129.]

Given two semigroupsfrom which:Gand_{1}= [S, ]G, an invertible function_{2}= [T, ]: S &rarr Tis said to be anisomorphismbetweenGand_{1}Gif, for every_{2}aandbinS,

(a b) = (a) (b)