Article ID Journal Published Year Pages File Type
438443 Theoretical Computer Science 2014 20 Pages PDF
Abstract

The well-known parsing algorithm for context-free grammars due to Valiant (1975) [25] is analyzed and extended to handle the more general Boolean grammars, which are context-free grammars augmented with conjunction and negation operators in the rules. The algorithm reduces construction of a parsing table to computing multiple products of Boolean matrices of various sizes. Its time complexity on an input string of length n   is O(BMM(n)logn), where BMM(n)BMM(n) is the number of operations needed to multiply two Boolean matrices of size n×nn×n, which is O(nω)O(nω) with ω<2.373ω<2.373 as per the current knowledge. A parse tree can be constructed in time MM(n)logO(1)n (where MM(n)MM(n) is the complexity of multiplying two integer matrices), by applying a known efficient procedure for determining witnesses for Boolean matrix multiplication. The algorithm has a succinct proof of correctness and is ready to be implemented.

Related Topics
Physical Sciences and Engineering Computer Science Computational Theory and Mathematics
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