Motion picture films generated by computers have now been produced by a number of groups across the country. We wish to report here on the design and implementation of the REL Animated Film Language (AFL), designed primarily for use by artists interested in the aesthetics of abstract motion graphics. The language is simple enough to be used by the artist directly, rather than by a professional programmer acting for the artist. It provides convenient means of expressing spatial and temporal changes in the shape and location of the objects with which the artist constructs his compositions. The artist uses the language to express the inter-object relationships which embody the aesthetic content of the work.

The techniques of automatic programming are useful for constructive proofs in automata theory. A formal definition of an elementary programming language for a stack automaton is given, and it is shown how this may be readily adapted to other classes of automata. The second part of this paper shows how this programming language can be applied to automata theory, as we prove there are non-context-sensitive languages accepted by a stack automaton.