English
The sequence of approximations is monotone nondecreasing with n: approx n x ≤ approx (n+1) x.
Русский
Последовательность аппроксимаций неубывает: approx n x ≤ approx(n+1) x.
LaTeX
$$$\\forall c\\, \\forall x:\\ approx(n,c,x) \\le approx(n+1,c,x)$$$
Lean4
theorem approx_le_succ (c : CU P) (n : ℕ) (x : X) : c.approx n x ≤ c.approx (n + 1) x := by
induction n generalizing c with
| zero =>
simp only [approx, right_U, right_le_midpoint]
exact (approx_mem_Icc_right_left c 0 x).2
| succ n ihn =>
rw [approx, approx]
exact midpoint_le_midpoint (ihn _) (ihn _)