Abstract
We investigate derivation-controlled $K$-iteration grammars, called $(\Gamma,K)$-iteration grammars, where $\Gamma$ can be any family of control languages. We prove that already under very weak restrictions on $\Gamma$ and $K$ the following hold: (i) Regular control does not increase the generating power of $K$-iteration grammars, (ii) for each $(\Gamma,K)$-iteration grammar there exists an equivalent propagating $(\Gamma,K)$-iteration grammar, (iii) the family of $(\Gamma,K)$-iteration languages is a full hyper-AFL, (iv) for each $(\Gamma,K)$-iteration grammar there exists an equivalent $(\Gamma,K)$-iteration grammar with exactly two substitutions. We also discuss some additional properties and applications of (uncontrolled) $K$-iteration grammars and controlled (deterministic) ET0L systems and their languages in a wider context.
Original language | English |
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Pages (from-to) | 248-269 |
Number of pages | 22 |
Journal | Information and Control |
Volume | 34 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1977 |
Keywords
- HMI-SLT: Speech and Language Technology
- MSC-68A30