Section CaseSum.
Variable (X Y : Type) (sigX sigY : finType) (codX : codable sigX X) (codY : codable sigY Y).

Lemma CaseSum_SpecT_size (s : X+Y) (ss : Vector.t nat 1) :
TripleT
(≃≃(([], withSpace  [|Contains _ s |] ss))) (CaseSum_steps) (CaseSum sigX sigY)
(fun yout => ≃≃([yout = if s then true else false],withSpace
(match s with inl x => [|Contains _ x|] | inr y =>  [|Contains _ y|] end)
(appSize [|S|] ss))).