Proof of proveit.logic.sets.functions.bijections.bijection_is_injection theorem

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

%proving bijection_is_injection

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

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