Proof of proveit.logic.booleans.implication.iff_f_f theorem

import proveit
from proveit.logic.booleans.implication import false_iff_false
theory = proveit.Theory() # the theorem's theory

%proving iff_f_f

With these allowed/disallowed theorem/theory presumptions (e.g., to avoid circular dependencies), we begin our proof of
iff_f_f:
(see dependencies)

iff_f_f may now be readily provable (assuming required theorems are usable).  Simply execute "%qed".

%qed

proveit.logic.booleans.implication.iff_f_f has been proven.

	step type	requirements	statement
0	instantiation	1, 2	⊢
	:
1	axiom		⊢
	proveit.logic.booleans.eq_true_intro
2	theorem		⊢
	proveit.logic.booleans.implication.false_iff_false