∀ (x n n' : ℤ),
  n + x = n' →
    ∀ (p q : ℤ),
      (ComplexShape.up ℤ).π (ComplexShape.up ℤ) (ComplexShape.up ℤ) (p, q) = n' →
        (ComplexShape.up ℤ).π (ComplexShape.up ℤ) (ComplexShape.up ℤ) (p - x, q) = n