SCHWA: PETE Using CCG Dependencies with the C&C Parser

This paper describes the SCHWA system entered by the University of Sydney in SemEval 2010 Task 12 -- Parser Evaluation using Textual Entailments (Yuret et al., 2010). Our system achieved an overall accuracy of 70% in the task evaluation. We used the C&C parser to build CCG dependency parses of the truth and hypothesis sentences. We then used partial match heuristics to determine whether the system should predict entailment. Heuristics were used because the dependencies generated by the parser are construction specific, making full compatibility unlikely. We also manually annotated the development set with CCG analyses, establishing an upper bound for our entailment system of 87%.