import logic namespace N1 variable num : Type.{1} variable foo : num → num → num end N1 namespace N2 variable val : Type.{1} variable foo : val → val → val end N2 using N1 using N2 variables a b : num variable f : num → val coercion f definition aux2 := foo a b check aux2 theorem T3 : aux2 = N1.foo a b := refl _