Theorem: LO.FirstOrder.Arith.Model.union_comm (Arithmetization/ISigmaOne/HFS/Basic.lean)

State before:
M : Type u_1
inst✝⁵ : Zero M
inst✝⁴ : One M
inst✝³ : Add M
inst✝² : Mul M
inst✝¹ : LT M
inst✝ : M ⊧ₘ* 𝐈𝚺₁
a b : M
⊢ ∀ (i : M), i ∈ a ∪ b ↔ i ∈ b ∪ a
Tactic:
simp [or_comm]
State after:
no goals