Theorem: LO.FirstOrder.Arith.Model.pi₁_pair (Arithmetization/Basic/IOpen.lean)

State before:
M : Type u_1
inst✝⁶ : Zero M
inst✝⁵ : One M
inst✝⁴ : Add M
inst✝³ : Mul M
inst✝² : LT M
inst✝¹ : M ⊧ₘ* 𝐏𝐀⁻
inst✝ : M ⊧ₘ* 𝐈open
a b : M
⊢ π₁⟪a, b⟫ = a
Tactic:
simp [pi₁]
State after:
no goals