rcases this with (rfl | rfl) <;> simp
case neg
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* 𝐈open
p : M
hp : ¬1 < p
this : p = 0 ∨ p = 1
⊢ Pow2 p ↔ p = 1
no goals