Symbol Manipulation in an Interactive Environment

In an interactive environment the opportunity exists for the on-line execution of an algorithm represented as a sequence of ordered commands. In particular, when the sequence of commands defines a normal Markov algorithm, the on-line environment provides a practical testing ground for one of the basic theories of computation. In order to develop and run a Markov algorithm a specification is required which will be capable of execution by a computer. One possibility is to represent the Markov algorithm and its data as a sequence of LISP S-expressions and to process the S-expressions using an extended LISP interpreter. In this paper the translation of Markov algorithms to LISP S-expressionsis discussed along with a minimum set of commands for a Markov processor. Some of the difficulties in constructing more complicated algorithms are also discussed and several enhancements are suggested which would make the resultant Markov processor more practical and easier to use.