Theorem: Encodable.fintypeArrowEquivFinArrow'_app (Logic/Vorspiel/Computability.lean)

State before:
ι : Type u_1
inst✝² : Fintype ι
inst✝¹ : DecidableEq ι
inst✝ : Encodable ι
α : Sort u_2
k : ℕ
hk : Fintype.card ι = k
f : ι → α
i : Fin k
⊢ (fintypeArrowEquivFinArrow' hk) f i = f (fintypeEquivFin.symm (Fin.cast ⋯ i))
Tactic:
rcases hk with rfl
State after:
ι : Type u_1
inst✝² : Fintype ι
inst✝¹ : DecidableEq ι
inst✝ : Encodable ι
α : Sort u_2
f : ι → α
i : Fin (Fintype.card ι)
⊢ (fintypeArrowEquivFinArrow' ⋯) f i = f (fintypeEquivFin.symm (Fin.cast ⋯ i))

State before:
ι : Type u_1
inst✝² : Fintype ι
inst✝¹ : DecidableEq ι
inst✝ : Encodable ι
α : Sort u_2
f : ι → α
i : Fin (Fintype.card ι)
⊢ (fintypeArrowEquivFinArrow' ⋯) f i = f (fintypeEquivFin.symm (Fin.cast ⋯ i))
Tactic:
rfl
State after:
no goals