Restricted Global Grammar Constraints

We investigate the global GRAMMAR constraint over restricted classes of context free grammars like deterministic and unambiguous context-free grammars. We show that detecting disentailment for the GRAMMAR constraint in these cases is as hard as parsing an unrestricted context free grammar. We also consider the class of linear grammars and give a propagator that runs in quadratic time. Finally, to demonstrate the use of linear grammars, we show that a weighted linear GRAMMAR constraint can efficiently encode the EDITDISTANCE constraint, and a conjunction of the EDITDISTANCE constraint and the REGULAR constraint.

• Type: Conference
• Year: 2009
• Where: CP
• Authors: George Katsirelos, Sebastian Maneth, Nina Narodytska, Toby Walsh
• Keywords: CP 2009, Global Grammar Constraint, Linear Grammar Constraint, Programming Languages, Unambiguous Context-free Grammars