Theorem: LO.FirstOrder.Arith.Model.domain_insert (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
x y s : M
⊢ domain (insert ⟪x, y⟫ s) = insert x (domain s)
Tactic:
simp [insert_eq_union_singleton]
State after:
no goals