Proof of proveit.linear_algebra.scalar_multiplication.doubly_scaled_as_singly_scaled theorem

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

%proving doubly_scaled_as_singly_scaled

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