Flowchart of a mass particle with M_r, ini = 16.53 M_⊙ (i.e. originally in the helium shell, cf. Fig. 1) and θ_ini = 3.15° at its temperature peak. Mass fractions of isotopes are shown by the red colourmap. Black squares denote stable isotopes. Net reaction rates, considering forward and reverse reactions, are shown by arrows. Arrows are coloured as a function of the reaction type: yellow for (α, γ), cyan for (n, γ), green for (α, n), and blue for (γ, α) and (n, α). Rates below 7 × 10²² cm s⁻¹ are not shown.