import Bookshelf.Real.Basic /-- Assert that a real number is rational. Note this does *not* require the found rational to be in reduced form. Members of `ℚ` expect this (by proving the numerator and denominator are coprime). -/ def rational (x : ℝ) := ∃ a : ℤ, ∃ b : ℕ, b ≠ 0 ∧ x = a / b /-- Assert that a real number is irrational. -/ def irrational (x : ℝ) := ¬ rational x