lect :: Ord a => Set a -> Endom (Skel a)
select cs = subst (substPred ((`notMember` cs), Zero) Act)


select :: Ord a => Set a -> Endom (Skel a)
select cs = subst (substPred ((`notMember` cs), Zero) Act)
select cs = subst (substPred ((`notMember` cs), Zero) Act)