Fuzzy context-free languages - Part 2: Recognition and parsing algorithms

In a companion paper [9] we used fuzzy context-free grammars in order to model grammatical errors resulting in erroneous inputs for robust recognizing and parsing algorithms for fuzzy context-free languages. In particular, this approach enables us to distinguish between small errors (“tiny mistakes”) and big errors (“capital blunders”). In this paper we present some algorithms to recognize fuzzy context-free languages: particularly, a modification of Cocke–Younger–Kasami’s algorithm and some recursive descent algorithms. Then we extend these recognition algorithms to corresponding parsing algorithms for fuzzy context-free languages. These parsing algorithms happen to be robust in some very elementary sense.