Proof of proveit.numbers.negation.distribute_neg_through_binary_sum theorem

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

%proving distribute_neg_through_binary_sum

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

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