exact Partial.mem_iff.mpr ⟨_, obj?_some_extend ‹_› ‹_›⟩
case mutNest
α : Type
inst✝ : Hierarchical α
rtr rtr₁ : α
rcn₁ rcn₂ : ID
i✝ : Component.idType Component.rtr
rtr₁✝ : Component.type α Component.rtr
j✝ : ID
rtr₂✝ : Component.type (Component.type α Component.rtr) Component.rtr
iₘ✝ : ID
m✝ : Component.type (Component.type α Component.rtr) Component.rcn
iᵣ✝ : ID
a✝⁴ : rtr[Component.rtr][i✝] = some rtr₁✝
a✝³ : rtr₁✝{Component.rtr}{j✝} = some rtr₂✝
a✝² : rtr₁✝{Component.rcn}{iₘ✝} = some m✝
a✝¹ : Reaction.Mutates m✝
a✝ : iᵣ✝ ∈ rtr₂✝{Component.rcn}
⊢ iₘ✝ ∈ rtr[Component.rcn]
no goals