Theorem: LO.FirstOrder.Arith.Model.sq_eq_one_iff (Arithmetization/Vorspiel/Lemmata.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* 𝐏𝐀⁻
a✝ b c a : M
⊢ a ^ 2 = 1 ↔ a = 1
Tactic:
simp [sq]
State after:
no goals