Theorem true_imp_true_iff_true ≪ | index | src | ≫

\imp真值表：\true \imp \true \iff \true

theorem true_imp_true_iff_true: $ \true \imp \true \iff \true $;

Step	Hyp	Ref	Expression
1		prov_iff_true	(\true \imp \true) \imp (\true \imp \true \iff \true)
2		imp_refl	\true \imp \true
3	1, 2	ax_mp	\true \imp \true \iff \true

Axiom use

Logic (ax_mp, ax_1, ax_2, ax_3)