Parameters not allowed in the declaration of a definable symbol

[Frédéric Blanqui]

Prop:Type.
def Prf:Prop -> Type.
N:Type.
eq:N -> N -> Prop.
def add:N -> N -> N.
add_com1 (x:N) (y:N) : Prf(eq (add x y) (add y x)).
def add_com2 (x:N) (y:N) : Prf(eq (add x y) (add y x)). (; fails ;)