General properties of derivational complexity

SummaryThe purpose of this paper is to establish a certain correspondence between shortest derivations of phrase structure grammars and Turing machine computations, and to show how to connect the derivational complexity introduced by Gladkij to Blum's axioms for partial recursive functions and their step-counting functions. It is shown that main theorems on Blum's axiomatic theory of computational complexity can be transfered to the case of derivational complexity.