Theorem and_def ≪ | index | src | ≫

\and定义式

theorem and_def (A B: wff): $ A \and B \iff \neg (A \imp \neg B) $;

Step	Hyp	Ref	Expression
1		iff_refl	\neg (A \imp \neg B) \iff \neg (A \imp \neg B)
2	1	conv and	A \and B \iff \neg (A \imp \neg B)

Axiom use

Logic (ax_mp, ax_1, ax_2, ax_3)