Theorem: LO.FirstOrder.Arith.Model.Disjoint.singleton_iff (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
s a : M
⊢ Disjoint {a} s ↔ a ∉ s
Tactic:
simp [Disjoint, isempty_iff]
State after:
no goals