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

import proveit
theory = proveit.Theory() # the theorem's theory

%proving iff_symmetry

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

iff_symmetry.instance_expr.prove(assumptions=iff_symmetry.conditions)

 ⊢  

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

%qed

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

	step type	requirements	statement
0	generalization	1	⊢
1	instantiation	2, 3, 4	⊢
	: , :
2	theorem		⊢
	proveit.logic.booleans.implication.iff_intro
3	instantiation	5, 7	⊢
	: , :
4	instantiation	6, 7	⊢
	: , :
5	theorem		⊢
	proveit.logic.booleans.implication.iff_implies_left
6	theorem		⊢
	proveit.logic.booleans.implication.iff_implies_right
7	assumption		⊢