Derivational complexity of context-free grammars

Complexity of Context − Free Grammars with Exceptions

This report has been submitted forr publication outside of ITC and will probably be copyrighted if accepted for publication. It has been issued as a Technical Report forr early dissemination of its contents. In view of the transfert of copy right too the outside publisher, its distribution outside of ITC priorr to publication should be limited to peer communications and specificc requests. Afte...

Complexity of Context - free Grammars with Exceptionsand

This report has been submitted forr publication outside of ITC and will probably be copyrighted if accepted for publication. It has been issued as a Technical Report forr early dissemination of its contents. In view of the transfert of copy right too the outside publisher, its distribution outside of ITC priorr to publication should be limited to peer communications and specificc requests. Afte...

Complexity of Uniform Membership of Context-Free Tree Grammars

We show that the uniform membership problem of context-free tree grammars is PSPACE-complete. The proof of the upper bound is by construction of an equivalent pushdown tree automaton representable in polynomial space. With this technique, we can also give an alternative proof that the respective nonuniform membership problem is in NP. A corollary for uniform membership of "-free indexed grammar...

A Measure of Structural Complexity for Context-free Grammars

On the Complexity of pure 2D Context-free Grammars

Picture languages generalize classical string languages to two-dimensional arrays. Several approaches have been proposed during the years; consequently, a general classification and a detailed comparison of the classes proposed turns to be necessary. We studied in detail closure properties of (regular) pure 2D context-free grammars (R)P2DCFG [1], and the complexity of the membership problem [2].