(left-bound-info . ,ly:line-spanner::calc-left-bound-info)
(normalized-endpoints . ,ly:spanner::calc-normalized-endpoints)
(right-bound-info . ,ly:line-spanner::calc-right-bound-info)
+ (simple-Y . #t)
(stencil . ,ly:line-spanner::print)
(style . line)
(X-extent . #f)
(interfaces . (font-interface
gregorian-ligature-interface
ledgered-interface
+ ligature-head-interface
mensural-ligature-interface
note-head-interface
rhythmic-grob-interface