Orthogonal Negation in Vector Spaces for Modelling Word-Meanings and Document Retrieval Dominic Widdows author 2003-07 text Proceedings of the 41st Annual Meeting of the Association for Computational Linguistics Association for Computational Linguistics Sapporo, Japan conference publication widdows-2003-orthogonal 10.3115/1075096.1075114 https://aclanthology.org/P03-1018/ 2003-07 136 143