The equivalence problem for LL- and LR-regular grammars

The Equivalence Problem for LL- and LR-Regular Grammars

Questions whether or not two grammars belonging to a family of grammars generate the same language have extensively been studied in the literature. These problems are called equivalence problems and if there exists an algorithm which for each pair of grammars of this family gives an answer to this question then the equivalence problem for this family of grammars is said to be decidable. Otherwi...

The Equivalence Problem for LL - and L / ? - Regular Grammars

The equivalence problem for context-free grammars is “given two arbitrary grammars, do they generate the same language ?” Since this is undecidable in general attention has been restricted to decidable subclasses of the context-free grammars. For example, the classes of U(k) grammars and real-time strict deterministic grammars. In this paper it is shown that the equivalence problem for U-regula...

Tests for the LR-, LL-, and LC-Regular Conditions

Most of the linear time parsing strategies (e.g., LL(k) and U(k) type parsers) for context-free grammars operate by looking ahead on the input tape for a fixed number of symbols. The fixed length look-ahead strings partition the set of input strings into classes of strings which are equivalent with respect to parsing decisions. A moment’s thought shows that these look-ahead classes are regular ...

On the Parsing of LL-Regular Grammars

On the Relationship Between the LL(k) and LR(k) Grammars

* The preparation of this paper was partially supported by a Natural Sciences and Engineering Research Council of Canada Grant No. A-7700 during the author’s stay at Mcc Master University, Hamilton, Ontario. remarked that a careful and clear proof of this inclusion result would make a suitable master’s thesis. We give a short survey of the relevant literature on this inclusion problem. From the...