이 름 전자우편 홈페이지 제목 비밀번호 (최소 4자이상의 영문 또는 숫자) Tom: very interesting points. Not sure what is to be concluded but I noticed that you both refer to material implication and entailment. When I quickly looked for entailment in the wikipedia, I understood that if S1 is inconsistent then S1 entails S2. Did I get it wrong or do you have something else in mind when you talk about entailment?