The composition of semantics in Algol 68
The main features of Algol 68 are explained from a semantic point of view. It is shown how the language permits the composition of values and actions, i.e. ultimately programs, from a minimum set of primitives with a few fundamental recursive rules of composition. The associated syntax is briefly reviewed. An attempt has been made to obtain a structured and simple introduction to both Algol 68 and its orthogonal desgn.