noncomp_theory.lean:4:0: error: definition 'f' is noncomputable, it depends on 'real.real_has_div'
noncomputable definition g : ℝ → ℝ → ℝ :=
λ (a : ℝ), div (a + a)
definition r : ℕ → ℕ :=
λ (a : ℕ), a