Theorem: getColumn2_spec2 (Table/Proofs.lean)

State before:
η : Type u_η
dec_η : DecidableEq η
sch : Schema
⊢ ∀ {τ : Type u} (t : Table sch) (c : η) (h : Schema.HasCol (c, τ) sch), List.length (getColumn2 t c) = nrows t
Tactic:
intro τ t c h
State after:
η : Type u_η
dec_η : DecidableEq η
sch : Schema
τ : Type u
t : Table sch
c : η
h : Schema.HasCol (c, τ) sch
⊢ List.length (getColumn2 t c) = nrows t

State before:
η : Type u_η
dec_η : DecidableEq η
sch : Schema
τ : Type u
t : Table sch
c : η
h : Schema.HasCol (c, τ) sch
⊢ List.length (getColumn2 t c) = nrows t
Tactic:
simp only [getColumn2, nrows, Schema.length_eq_List_length]
State after:
η : Type u_η
dec_η : DecidableEq η
sch : Schema
τ : Type u
t : Table sch
c : η
h : Schema.HasCol (c, τ) sch
⊢ List.length (List.map (fun r => getValue r c) t.rows) = List.length t.rows

State before:
η : Type u_η
dec_η : DecidableEq η
sch : Schema
τ : Type u
t : Table sch
c : η
h : Schema.HasCol (c, τ) sch
⊢ List.length (List.map (fun r => getValue r c) t.rows) = List.length t.rows
Tactic:
apply List.length_map
State after:
no goals