Natural Negation Modeling and Processing



The main objective of the NEXING project is to contribute for improving the automated mapping between (orthographic) form and (linguistic) meaning, on the one hand, and between (linguistic) meaning and knowledge (representation), on the other hand, in what concerns natural language negation.

The processing of natural negation offers some of its most notable puzzles at the interfaces of Semantics with Syntax and Pragmatics. Note that negation may be expressed only once although several negative expressions are involved, as in the so-called negative concord constructions such as Port.: "Nunca ninguém lê as propostas com atenção" / lit.: "Never nobody reads the proposals with attention" / "Nobody ever reads proposals attentively". On the other hand, negation can be expressed even though no overt negative expression occurs, as in the so-called counterfactual conditionals such as "If Clara had arrived, Rui would be happier" - a construction without overt negative expressions that nevertheless informs, among other things, that Clara did not come. Also the interface between language and cognition offers significant challenges in this respect since negation is at the heart both of several quantification-based linguistic phenomena and of the operations of formal thought (attained by 11-14 year old children), although the implications of these deep commonalties between language and cognition have been waiting to be fully clarified.

NEXING is a multi-disciplinary project fostering the convergence of methods, results and expertise from Informatics, Applied Logic, Cognitive Psychology and Formal Linguistics in the areas of the lexicon, syntax, semantics, pragmatics and reasoning. The workplan is divided into several tasks covering Negative Concord and Polarity, Counterfactuals, Deductive Inference, Computational Modeling, and Language Engineering Resources Development (Corpus and Linguistic Database).


Research centers
Given its intrinsic multidisciplinary program, the NEXING project is a common enterprise of three academic research centers affiliated with three Universities: University of Algarve (UALG), University of Coimbra (UC) and University of Lisbon (UL).
The participating centers have been conducting research on artificial intelligence, cognitive science and natural language science and technology:
The IPCDVS-Institute for Cognitive Psychology is a research institute of the Faculty of Psychology and Education Sciences of Coimbra, UC; the LabMAC-Laboratory of Computational Models and Architectures is hosted by the Department of Informatics of the Faculty of Sciences of Lisbon, UL; and the UCH-Faculty of Human Sciences is a division of UALG.

António Horta Branco (coord.), UL
Luís Miguel Gomes, UC
José Leitão, UC
Pedro Santos, UALG
João Silva, UL
Ana Paula Silveira, UC


The project is funded by the FCT-Foundation for Science and Technology of the MCT-Portuguese Ministery of Science and Technology under the contract FCT/SAPIENS99/34076/99. The project life is planned to span over 24 months. Check here for a press release of FCT about the project.

Results (June 2003)


Journal (special issue) Presentations Software Language Engineering Resources


Cooperation with related projects

Visiting scholars Availability


International seminars

Open meetings