SLE boundary swallowing criterion ($\{\gamma \cap [b,\infty )\ne \varnothing \}=\{T_b<\infty \}$)

For a continuous chordal SLE trace started at zero, hitting the real interval $[b,\infty )$ is equivalent to finite boundary-point swallowing time for a Loewner chain at $b>0$. A boundary crosscut may swallow all points between its endpoints without visiting them individually. The Boundary-point Bessel flow for SLE determines the probability of this event.