namespace Any
  export
  strengthL : Any.Maybe a  b =&> Any.Maybe (a  b)
  strengthL = !! \case (Nothing && p2) => Nothing ## absurd
                       ((Just x) && p2) => Just (x && p2) ## \(Aye y) => Aye y.π1 && y.π2
 
  export
  strengthR : a  Any.Maybe b =&> Any.Maybe (a  b)
  strengthR = !! \case (p1 && Nothing) => Nothing ## absurd
                       (p1 && (Just x)) => Just (p1 && x) ## \(Aye y) => y.π1 && Aye y.π2
 
 
-- there is no strength for All.Maybe
namespace All
 failing
  export
  strength : All.Maybe a  b =&> All.Maybe (a  b)
  strength = !! \case (Nothing && p2) => Nothing ## \case (Nay) => Nay && ()
                      ((Just x) && p2) => ?strengthL_rhs_2