unfoldf.lean:10:2: proof state
a b : ℕ,
H : a = b
⊢ a = b
unfoldf.lean:17:2: proof state
a b : ℕ,
H : a = b
⊢ (id ∘ id) a = b
unfoldf.lean:26:2: proof state
a b : ℕ,
H : a = b
⊢ a = b