Coverage-Based Semi-distance between Horn Clauses

In the present paper we use the approach of height functions to de ning a semi distance measure between Horn clauses This appraoch is already discussed elsewhere in the framework of propositional and sim ple rst order languages atoms Hereafter we prove its applicability for Horn clauses We use some basic results from lattice theory and introduce a family of language independent coverage based height functions Then we show how these results apply to Horn clauses We also show an exam ple of conceptual clustering of rst order atoms where the hypotheses are Horn clauses