simp [State.unprocessed, Equivalent.obj?_rcn_eq e.equiv, and_assoc, e.progress_eq]
case h
α : Type
inst✝ : Hierarchical α
s₁ s₂ : State α
e : s₁ ↓ₑ s₂
i : ID
⊢ i ∈ unprocessed s₂ ↔ i ∈ unprocessed s₁ \ {rcn e}
case h
α : Type
inst✝ : Hierarchical α
s₁ s₂ : State α
e : s₁ ↓ₑ s₂
i : ID
⊢ i ∈ s₂.rtr[Component.rcn] → (i ∉ Set.insert (rcn e) s₁.progress ↔ i ∉ s₁.progress ∧ ¬i = rcn e)