A Three-Valued Interpretation of Negation in Feature Structure Descriptions Anuj Dawar author K Vijay-Shanker author 1989-06 text 27th Annual Meeting of the Association for Computational Linguistics Association for Computational Linguistics Vancouver, British Columbia, Canada conference publication dawar-vijay-shanker-1989-three 10.3115/981623.981626 https://aclanthology.org/P89-1003/ 1989-06 18 24