Let us look at a special type of context sensitive grammars, the so-called Definite Clause Grammars, or DCG, as described by Pereira and Warren (l980). The following question seems natural here: every context sensitive language be described by meeins of a definite clause grammar ? The question must be answered in the eiffirmative, as can be seen by simu lating Turing machines or better Markov ...