Interlocking source function description of the Ly-γ spectral line synthesized from the FALC atmosphere. Panel (a) shows the contribution to interlocking by the different intermediate states, expressed by Eq. (38) and higher-order paths, expressed by Eq. (41). γ₂ and γ₃ refers to the intermediate states n = 2 and n = 3. ω₁ and ω₂ connected to γ₃ refer to the first-order path p₃₁(1 − p₂₅p₅₂) and p₃₄(1 − p₂₅p₅₂) and second-order path p₃₂p₂₁ and p₃₂p₂₄, respectively. ω₁ connected to γ₂ refers to the first-order path connected to p₂₁(1 − p₃₅p₅₃) and p₂₄(1 − p₃₅p₅₃). Panel (b) shows the contributions to the “total” interlocking source function by ω₁ through the intermediate state n = 2 as well as ω₁ and ω₂ through the intermediate state n = 3.