definition bla.f : ℕ → ℕ :=
λ a, a + 1
definition bla.f [reducible] : ℕ → ℕ :=
λ a, a + 1
definition bla.f : ℕ → ℕ :=
λ a, a + 1
definition bla.f [reducible] : ℕ → ℕ :=
λ a, a + 1