instance
definition
def or abbrev
rational_computable
show as:
view Lean formalization →
formal statement (Lean)
141instance rational_computable (q : ℚ) : Computable (q : ℝ) where
142 approx := ⟨fun _ => q, by
proof body
Definition body.
143 intro k
144 simp only [sub_self, abs_zero]
145 exact two_zpow_pos _⟩
146
147/-! ## Closure Properties -/
148
149/-- Negation is computable: approximate -x by -f(n). -/