(,ly:axis-group-interface::calc-staff-staff-spacing . ,ly:axis-group-interface::calc-pure-staff-staff-spacing)
(,ly:axis-group-interface::height . ,ly:axis-group-interface::pure-height)
(,ly:beam::rest-collision-callback . ,ly:beam::pure-rest-collision-callback)
(,ly:axis-group-interface::calc-staff-staff-spacing . ,ly:axis-group-interface::calc-pure-staff-staff-spacing)
(,ly:axis-group-interface::height . ,ly:axis-group-interface::pure-height)
(,ly:beam::rest-collision-callback . ,ly:beam::pure-rest-collision-callback)