entrytree_fold_loc_ l f v (e:et) = 
    let vn = f l v (entrytree_thisentry e)
        lu = (loc_firstunder l)
        vu = entrytree_fold_loc_ lu f vn (entrytree_children e)
    in entrytree_fold_loc_ (loc_after l) f vu et
entrytree_fold_loc_ l f v (e:et) = 
    let vn = f l v (entrytree_thisentry e)
        lu = (loc_firstunder l)
        vu = entrytree_fold_loc_ lu f vn (entrytree_children e)
    in entrytree_fold_loc_ (loc_after l) f vu et
entrytree_fold_loc_ l f v (e:et) = 
    let vn = f l v (entrytree_thisentry e)
        lu = (loc_firstunder l)
        vu = entrytree_fold_loc_ lu f vn (entrytree_children e)
    in entrytree_fold_loc_ (loc_after l) f vu et