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.

Theorem mod2_WS : forall sz (x : word sz) b, mod2 (wordToNat (WS b x)) = b.