menu-max-fold-lines -- Return an approximation of the number of menuitems that will fit vertically on screen.
sorted-by-car-string -- Sort the elements of list L based on the string value of their car.
fold-menu-list -- Split ML into chained menus of no more than MAX-LINES items.
split-list-by-group -- Split the a-list LS into groups according to the car of each of its cells.
fold-menu-list-by-group -- Split ML-CONS into chained menus based on their group.