Proof of proveit.logic.booleans.negation.negation_intro theorem

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

%proving negation_intro

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

AeqF = negation_intro.condition

AeqF:

not_false

 ⊢  

AeqF.sub_left_side_into(not_false, assumptions=[AeqF])

 ⊢  

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

%qed

proveit.logic.booleans.negation.negation_intro has been proven.

	step type	requirements	statement
0	generalization	1	⊢
1	instantiation	2, 3, 4	⊢
	: , : , :
2	theorem		⊢
	proveit.logic.equality.sub_left_side_into
3	conjecture		⊢
	proveit.logic.booleans.negation.not_false
4	assumption		⊢