CURT (Clever Use of Reasoning Tools)
The CURT (Clever Use of Reasoning Tools) family  is a series of simple dialogue systems which illustrate how tools for building semantic representations can be combined with inference tools.
The behaviour of the different CURT programs is as follows: the user extends CURT's knowledge by entering English sentences, and can query it about its acquired knowledge.
The CURT family is composed of Baby Curt (the backbone of the Curt system using no inference services), Rugrat Curt (including either a simple free variable tableau prover or resolution prover to check the consistency of the current dialog), Clever Curt (which performs consistency checking by running a sophisticated first-order theorem prover and model checker in parallel), Sensitive Curt (which checks in addition for informativeness of the discourse), Scrupulous Curt (which eliminates equivalent interpretations), Knowledgeable Curt (which adds lexical and world knowledge) and Helpful Curt (which is able to handle simple natural language questions from the user). A number of versions of CURT (covering French, Romanian and Spanish) have been also developed.
More recently, a Polish version of CURT has been developed. This improves on previous versions in a number of ways. First, the Prolog-based beta-reduction module has been replaced by the use of Nessie, which permits proper typing to lambda terms. Secondly, for the first time CURT has been extended to cover representation and inference for temporal phenomena in natural language. In fact, this new version updates CURT so thoroughly, that it is likely to eventually displace the old system entirely.
Web site: http://www.comsem.org
Authors: Carlos Areces, Patrick Blackburn, Johan Bos (University of Bologna), Sébastien Hinderer
Contact: Carlos Areces, Patrick Blackburn, Sébastien Hinderer.