Hauber’s law
Hauber’s law
Given a set of conditional sentences A1 ? B1, A2 ? B2, . . . , An ? Bn, we may infer each of the conditional sentences B1 ? A1, B2 ? A2, . . . , Bn ? An, provided we know that A1, A2, . . . , An are exhaustive and B1, B2, . . . , Bn are mutually exclusive — i.e., provided we have also A1 ? A2 ? . . . ? An and ~[B1B2], ~[B1B3], . . . , ~[Bn-1Bn]. This form (or set of forms) of valid inference of the propositional calculus is Hauber’s law. — A.C.