Hydra: a Modal Logic Tool for Wordnet Development, Validation and Exploration Borislav Rizov author 2008-05 text Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC’08) Nicoletta Calzolari editor Khalid Choukri editor Bente Maegaard editor Joseph Mariani editor Jan Odijk editor Stelios Piperidis editor Daniel Tapias editor European Language Resources Association (ELRA) Marrakech, Morocco conference publication rizov-2008-hydra https://aclanthology.org/L08-1350/ 2008-05