Proof of proveit.numbers.division.strong_div_from_denom_bound__neg_over_pos theorem

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

%proving strong_div_from_denom_bound__neg_over_pos

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