Extended context free grammars are obtained by allowing regular expressions on the right hand sides of production rules of context free grammars. The LR(k) and LL(k) conditions are made applicable toâ€¦ (More)

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 lengthâ€¦ (More)

The problem whether there exists a unifying substitution for two terms is considered in the class of theories which can be embedded into canonical term rewriting systems. The problem is shown to beâ€¦ (More)

A refinement of Pager's method for the elimination of chain productions from LR parsers is presented. A practical algorithm is given and it is shown that the resulting parsers are prefix-correct in aâ€¦ (More)

The traditional complement construction for $LR(1)$ grammars is long and tedious and causes all of the structure of the original grammar to be lost. A new construction method is introduced whichâ€¦ (More)

An extended regular expression is a regular expression containing additional operator symbols for complementation (relative to E*) and intersection. Since the regular sets are closed underâ€¦ (More)