Design and construction of an error-free compiler is a difficult and challenging process. The main functionality of a compiler is to translate a source code to an executable machine code correctly and efficiently. In ...Design and construction of an error-free compiler is a difficult and challenging process. The main functionality of a compiler is to translate a source code to an executable machine code correctly and efficiently. In formal verification of software, semantics of a language has more meanings than the syntax. It means source program verification does not give guarantee the generated code is correct. This is because the compiler may lead to an incorrect target program due to bugs in itself. It means verification of a compiler is much more important than verification of a source program. In this paper, we present a new approach by linking context-free grammar and Z notation to construct LR(K) parser. This has several advantages because correctness of the compiler depends on describing rules that must be written in formal languages. First, we have defined grammar then language derivation procedure is given using right-most derivations. Verification of a given language is done by recursive procedures based on the words. Ambiguity of a language is checked and verified. The specification is analyzed and validated using Z/Eves tool. Formal proofs are presented using powerful techniques of reduction and rewriting available in Z/Eves.展开更多
A new tagging method is presented to build a Chinese semantic corpus. The method characterizes the sentence meaning as a linear sequence of dependency relationships which are the semantic or syntactic relationships b...A new tagging method is presented to build a Chinese semantic corpus. The method characterizes the sentence meaning as a linear sequence of dependency relationships which are the semantic or syntactic relationships between words in the sentence. This representation method is used to build a Chinese statistical parser model to understand the sentence meaning. Specific experiments on automatic telephone switchboard conversations show that the proposed parser has a precision of 80%. This work provides a foundation for building a large-scale Chinese semantic corpus and for research on understanding modeling of the Chinese language.展开更多
文摘Design and construction of an error-free compiler is a difficult and challenging process. The main functionality of a compiler is to translate a source code to an executable machine code correctly and efficiently. In formal verification of software, semantics of a language has more meanings than the syntax. It means source program verification does not give guarantee the generated code is correct. This is because the compiler may lead to an incorrect target program due to bugs in itself. It means verification of a compiler is much more important than verification of a source program. In this paper, we present a new approach by linking context-free grammar and Z notation to construct LR(K) parser. This has several advantages because correctness of the compiler depends on describing rules that must be written in formal languages. First, we have defined grammar then language derivation procedure is given using right-most derivations. Verification of a given language is done by recursive procedures based on the words. Ambiguity of a language is checked and verified. The specification is analyzed and validated using Z/Eves tool. Formal proofs are presented using powerful techniques of reduction and rewriting available in Z/Eves.
基金Supported by the National High- Technology DevelopmentProgram of China(No. 863 - 3 0 6- 2 D0 3 - 0 1- 2)
文摘A new tagging method is presented to build a Chinese semantic corpus. The method characterizes the sentence meaning as a linear sequence of dependency relationships which are the semantic or syntactic relationships between words in the sentence. This representation method is used to build a Chinese statistical parser model to understand the sentence meaning. Specific experiments on automatic telephone switchboard conversations show that the proposed parser has a precision of 80%. This work provides a foundation for building a large-scale Chinese semantic corpus and for research on understanding modeling of the Chinese language.
