no goals
α : Type u
β : α → Type v
inst✝ : DecidableEq α
s₁✝ s₂✝ s₃✝ : Finmap β
s₁ s₂ s₃ : AList β
⊢ ⟦s₁⟧ ∪ ⟦s₂⟧ ∪ ⟦s₃⟧ = ⟦s₁⟧ ∪ (⟦s₂⟧ ∪ ⟦s₃⟧)
simp only [AList.toFinmap_eq, union_toFinmap, AList.union_assoc]