Fact eq_rect_combine_dist_helper1 : forall a b c d, b * c = d -> (a + b) * c = a * c + d.Fact eq_rect_combine_dist_helper2 : forall a b c d, b * c = d -> a * c + d = (a + b) * c.

Lemma wzero_dist : forall a b c H, wzero ((a + b) * c) = eq_rect _ word (wzero (a * c + b * c)) _ H.