@article {191, title = {A Quasi-Metric for Machine Learning}, journal = {Lecture Notes in Computer Science}, volume = {2527}, year = {2002}, pages = {193-203}, publisher = {Springer}, address = {Amsterdam, The Netherlands}, abstract = {The subsumption relation is crucial in the Machine Learning systems based on a clausal representation. In this paper we present a class of operators for Machine Learning based on clauses which is a characterization of the subsumption relation in the following sense: The clause C1 subsumes the clause C2 iff C1 can be reached from C2 by applying these operators. In the second part of the paper we give a formalization of the closeness among clauses based on these operators and an algorithm to compute it as well as a bound for a quick estimation.}, isbn = {978-3-540-00131-7}, issn = {0302-9743}, doi = {10.1007/3-540-36131-6_20}, url = {http://dx.doi.org/10.1007/3-540-36131-6_20}, author = {Miguel A. Guti{\'e}rrez-Naranjo and Jos{\'e} A. Alonso-Jim{\'e}nez and Joaqu{\'\i}n Borrego-D{\'\i}az} }