0N/Avars a: Type; b: Type

0N/Atype i a b, Inj a b < a -> b

0N/Avars a: Type; b < a

292N/Aop twice: (a ->? b) -> (a ->? b)

0N/A

0N/Avars f: a ->? b; x: a

0N/A. twice f x = f (f x)

0N/A

292N/Avars a: Type; b: Type

292N/Atype Inj a b = {f: a -> b . forall x, y: a . f x = f y => x = y}

292N/A

292N/Avars a, b: Type; a < b

0N/Aop down: b ->? a

0N/Avar y: b; x: a

0N/A. down y = x

292N/A

292N/Aop up: a -> b

292N/A. down (up x : b) = x

292N/A. def (down (y : b) : a) => up (down y : a) = y

292N/A

292N/Avars c: Type; b < c

292N/A

292N/Avar x: a

292N/A. up (up x : b) = up x : c

292N/A. up (x: a) = x: b

292N/A

0N/Avars c, d, e, f; c < e; d < f

0N/Aforall f: e -> f . up : e ->? f = \ x : e . f x

0N/Aforall f: e ->? d . up f : c ->? f = \ x : c . up (f (up x))

0N/Aforall x: c; y: d . up (x, y) : e * f = (up x, up y)

0N/A