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Atlas.ComplexVariables.code.BridgeSingleSingularity

Bridge single singularity — verified re-export #

bridge_single_singularity_base is a proved theorem in Lecture14.lean, reduced from circleIntegral_eq_sum_of_singularities with Fin 1. This file re-exports the result for discoverability.

theorem bridge_single_singularity {c : ℂ} {R : ℝ} (hR : 0 < R) {a₀ : ℂ} {r₀ : ℝ} {f : ℂ → ℂ} (ha : a₀ ∈ Metric.ball c R) (hr : 0 < r₀) (hrd : Metric.closedBall a₀ r₀ ⊆ Metric.ball c R) (hcont : ContinuousOn f (Metric.closedBall c R \ {a₀})) (hdiff : ∀ z ∈ Metric.ball c R \ {a₀}, DifferentiableAt ℂ f z) :
∮ (z : ℂ) in C(c, R), f z = ∮ (z : ℂ) in C(a₀, r₀), f z

Non-concentric single-singularity contour deformation (re-export). The integral of f over C(c,R) equals the integral over C(a₀,r₀) when f is holomorphic on closedBall c R \ {a₀} and closedBall a₀ r₀ ⊆ ball c R.