| Abstrakt: |
In [1] and [2] D. Lewis formulates his counterfactual logic VCas follows. The language contains the connectives ?, ?, ?, ¬ and the binary connective =. A= Bis read as “Ais at least as possible as B”. The following connectives are defined in terms of =.A< B: = ¬(B= A) (it is more possible that Athan that B).? A? ¬(? = A) (? is the false formula; Ais possible).? A? ? = ¬A(Ais necessary).(if Awere the case, then Bwould be the case).(if Awere the case, then Bmight be the case).and are two counterfactual conditional operators. (AB) iff ¬(A¬B).The following axiom system VCis presented by D. Lewis in [1] and [2]: V: (1) Truthfunctional classical propositional calculus. |
