Fusion approach of formal semantics for the parsing of UDC sentences

Aiming at the problem that the currently available parsing methods have difficulty in obtaining the D-structure/meaning of UDC sentences, this paper puts forward the fusion approach of formal semantics (FAFS) which combines lambda-abstraction, lambda-calculus, HPSG (Head-Driven Phrase Structure Grammar), and knowledge in the realm of functional grammar. Firstly, employing the context-sensitive attribute grammar of HPSG, FAFS establishes the S-structure of UDCs, distinguishes between strong and weak UDCs, and extracts the fillers for the traces. Then FAFS obtains the WFF of UDCs according to the HPSG parse tree. In view of functional grammar, strong and weak UDCs are in fact ellipsis and substitution. With the result of HPSG parsing and filler extraction, as well as the WFF of UDCs, FAFS employs X-abstraction and X-calculus to derive the D-structure/meaning of a UDC and complete the parsing task. The overall computational efficiency of FAFS is in the cubic time, and thus FAFS is efficient. Finally, application examples were examined.