cases S
Hknown : known [] = true
S : List ℕ
Hrefines : shapeRefines S [] = true
⊢ [] = List.map Dimension.Known S
case nil
Hknown : known [] = true
Hrefines : shapeRefines [] [] = true
⊢ [] = List.map Dimension.Known []

case cons
Hknown : known [] = true
head✝ : ℕ
tail✝ : List ℕ
Hrefines : shapeRefines (head✝ :: tail✝) [] = true
⊢ [] = List.map Dimension.Known (head✝ :: tail✝)