theorem
proved
term proof
regularFactor_continuousPhase_exists
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formal statement (Lean)
133theorem regularFactor_continuousPhase_exists
134 (g : ℂ → ℂ) (c : ℂ) (R r : ℝ) (_hR : 0 < R) (_hr : 0 < r) (_hrR : r < R)
135 (_hg_diff : DifferentiableOn ℂ g (Metric.closedBall c R))
136 (_hg_nz : ∀ z ∈ Metric.closedBall c R, g z ≠ 0) :
137 ∃ (phase : ℝ → ℝ),
138 phase = (fun _ => 0) ∧
139 Continuous phase ∧
140 phase (2 * π) - phase 0 = 0 := by
proof body
Term-mode proof.
141 refine ⟨fun _ => 0, rfl, ?_, ?_⟩
142 · simpa using (continuous_const : Continuous fun _ : ℝ => (0 : ℝ))
143 · simp
144
145/-- The constant zero phase is Lipschitz with any positive bound. -/