induction sch with
| nil => simp [List.map, List.append]
| cons s ss ih =>
 simp only [List.map]
 rw [ih]
 simp [List.append]
 exact Table.mk []
 exact (λ x => f (Row.cons Cell.emp x))
η : Type u_η
dec_η : DecidableEq η
sch : Schema
τ : Type u
t : Table sch
c : η
f : Row sch → Option τ
⊢ List.map Prod.fst (Schema.append sch [(c, τ)]) = List.map Prod.fst sch ++ [c]
no goals