Axiomatization of Approximate Exclusion

We define and axiomatize approximate exclusion atoms in the team semantic setting. A team is a set of assignments, which can be seen as a mathematical model of a uni-relational database. We say that an approximate exclusion atom is satisfied in a team if the corresponding usual exclusion atom is satisfied in a large enough subteam. We consider the implication problem for a set of approximate exclusion atoms and show that it is axiomatizable for consequences with a degree of approximation that is not too large. We prove the completeness theorem for usual exclusion atoms, currently missing from the literature, and generalize it to the approximate case. We also provide a polynomial time algorithm for the implication problems. The results can also be applied to exclusion dependencies in database theory.