unfold decodeQuotient encodeQuotient
case h
n : Nat
s : Setoid (Fin n)
inst✝ : DecidableRel Setoid.r
k : Fin (quot s)
i : Fin n
⊢ decodeQuotient s k = Quotient.mk s i ↔ encodeQuotient s (Quotient.mk s i) = k
case h
n : Nat
s : Setoid (Fin n)
inst✝ : DecidableRel Setoid.r
k : Fin (quot s)
i : Fin n
⊢ Quotient.mk s (decodeSubtype (repr s) k).val = Quotient.mk s i ↔ (Quotient.mk s i).liftOn (Fin.getRepr s) ⋯ = k