Some concepts for languages more powerful than context-free

Some new restrictive devices for grammars are introduced: standard control-sets, G-control-sets, checking state grammars, besides the wellknown ones: matrix-sets, regular control-sets, programs. All these concepts turn out to be equivalent with respect to their generative power. So we get further characterizations of the class of recursively enumerable sets. The generative power of context-freelabel-grammars and Chomsky-grammars both with these restrictive devices is found to be equal. New characterizations of the unconditional-transfer programmed-grammars are introduced, namely unconditional-transfer programs correspond to all the other devices mentioned above under so-called “full-checking possibility” — i.e. the whole set of labels is the checking-set.