A Note on the Complexity of Restricted Attribute­Value Grammars
Leen Torenvliet, Marten Trautwein

The recognition problem for attribute­value grammars(AVGs) was shown to
be undecidable by Johnson in 1988. Therefore, the general form of AVGs is of
no practical use. In this paper we study a very restricted form of AVG, for 
which the recognition problem is decidable (though still NP­complete), the 
R­AVG. We show that the R­AVG formalism captures all of the context free 
languages and more, and introduce a variation on the so­called off­line 
parsability constraint , the honest parsability constraint , which lets 
different types of R­AVG coincide precisely with well­known time complexity 
classes.