fact: Definition msigT_of_msigT2 (A : Type) (P Q : A -> Type) (X : msigT2 P Q) : msigT P := mexistT P (let (a, _, _) := X in a) (let (x, p, _) as s return (P (let (a, _, _) := s in a)) := X in p).
imports: Notations Datatypes Logic