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

Lemma Constr_inl_SpecT_size (x : X) (ss : Vector.t nat 1) :
TripleT
(≃≃(([], withSpace  [|Contains _ x |] ss))) Constr_inl_steps (Constr_inl sigX sigY)
(fun _ => ≃≃(([], withSpace  [|Contains _ (inl (B:=Y)x)|] (appSize [|pred|] ss)))).