Approximate Reasoning Based on Similarity

The connection between similarity logic and the theory of closure operators is examined. Indeed one proves that the consequence relation dened in (14) can be obtained by composing two closure operators and that the resulting operator is still a closure oper- ator. Also, we extend any similarity into a similarity which is compatible with the logical equivalence, and we prove that this gives the same consequence relation. Mathematics Subject Classication: 03B52, 94D05,68T27.