Logic Form Transformation
Lymba's logic form transformation (LFT) tool translates natural language sentences into a first-order logic knowledge representation that is derived from a syntactic parse tree. Each word from the original sentence maps to a predicate in the logical form. The predicate names are a concantenation of the word, its part of speech, and word sense. The arguments of the predicate serve to preserve the syntactic properties of the sentence, such as prepositional attachments and modifiers.
Lymba's LFT tool is augmented with predicates that are not generated directly from the syntax of the sentence, but from the linguistic semantics of the sentence as detected by Lymba's named entity recognizer and semantic relation engine. As an example for the sentence:
An earthquake occurred on the east coast of Hokkaido.
Lymba's LFT generates the following first-order logic representation:
earthquake_NN(x1) & occur_VB(e1,x1,x4) & on_IN(e1,x2) & east_coast_NN(x2) & of_IN(x2,x3) & hokkaido_NN(x3) & _otherloc_NE(x3) & AGT_SR(x1,e1) & PW_SR(x2,x3) & LOC_SR(x2,e1)
For more details on logic forms please see:Mohammed, A.; Moldovan, D.; Parker, P. "Senseval 3 Logic Forms: A System and Possible Improvements", Third International Workshop on the Evaluation of Systems for the Semantic Analysis of Text, Barcelona, Spain, July 2004.