Theorem: LO.FirstOrder.Arith.Model.mem_singleton_iff (Arithmetization/ISigmaOne/Bit.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
i j : M
⊢ i ∈ {j} ↔ i = j
Tactic:
simp [singleton_eq_insert]
State after:
no goals