Theorem: Tutorial.map_inv (Tutorial/Advanced/Algebra/Lecture2.lean)

State before:
G₁ G₂ : Type
inst✝¹ : Group G₁
inst✝ : Group G₂
f : G₁ →* G₂
a : G₁
⊢ f a⁻¹ = (f a)⁻¹
Tactic:
sorry
State after:
no goals