Theorem false_or_false_iff_false ≪ | index | src | ≫

\or真值表：\false \or \false \iff \false

theorem false_or_false_iff_false: $ \false \or \false \iff \false $;

Step	Hyp	Ref	Expression
1		or_unify	\false \or \false \iff \false

Axiom use

Logic (ax_mp, ax_1, ax_2, ax_3)