via :: Eq d => (a -> b, c -> d) -> (c -> a, b -> d) -> c -> Bool
via (vf, lf) (f, g) c = (g . vf . f) c == lf c
via :: Eq d => (a -> b, c -> d) -> (c -> a, b -> d) -> c -> Bool
via (vf, lf) (f, g) c = (g . vf . f) c == lf c
via (vf, lf) (f, g) c = (g . vf . f) c == lf c