r : ℝ
hr : 0 < r
θ : ℝ
⊢ ↑(- -⌊(-π + 2 * π - θ) / (2 * π)⌋) * (2 * π) = 2 * π * ↑⌊(π - θ) / (2 * π)⌋
r : ℝ
hr : 0 < r
θ : ℝ
⊢ arg (↑r * (cos ↑θ + sin ↑θ * I)) - θ = 2 * π * ↑⌊(π - θ) / (2 * π)⌋
rw [arg_mul_cos_add_sin_mul_I_eq_toIocMod hr, toIocMod_sub_self, toIocDiv_eq_neg_floor,
  zsmul_eq_mul]
no goals
r : ℝ
hr : 0 < r
θ : ℝ
⊢ ↑(- -⌊(-π + 2 * π - θ) / (2 * π)⌋) * (2 * π) = 2 * π * ↑⌊(π - θ) / (2 * π)⌋
ring_nf