Set: pp::colors Set: pp::unicode Assumed: f Assumed: N Assumed: n1 Assumed: n2 Set: lean::pp::implicit f::explicit N n1 n2 f::explicit ((N → N) → N → N) (λ x : N → N, x) (λ y : N → N, y) Assumed: EqNice EqNice::explicit N n1 n2 f::explicit N n1 n2 : N Congr::explicit : Π (A : Type U) (B : A → Type U) (f g : Π x : A, B x) (a b : A), (f = g) → (a = b) → ((f a) = (g b)) f::explicit N n1 n2 Assumed: a Assumed: b Assumed: c Assumed: g Assumed: H1 Proved: Pr Axiom H1 : a = b ∧ b = c Theorem Pr : (g a) = (g c) := Congr::explicit N (λ x : N, N) g g a c (Refl::explicit (N → N) g) (Trans::explicit N a b c (Conjunct1::explicit (a = b) (b = c) H1) (Conjunct2::explicit (a = b) (b = c) H1))