and Γ (G ′ , H ′ , β), as well as all vertices in the reactant and product graphs within a same distance of at most r from a vertex in the reaction centers. Our starting point is Def. 9 in. Definition 2. For two reactions G H and G ′ H ′ , two partial AAMs π : U → W with U ⊆ V (G) and W ⊆ V (H), and π ′ :