static Interval relative_pure_height (Grob *me, int start, int end);
static Interval combine_pure_heights (Grob *me, SCM, int, int);
static Interval sum_partial_pure_heights (Grob *me, int, int);
static Interval relative_pure_height (Grob *me, int start, int end);
static Interval combine_pure_heights (Grob *me, SCM, int, int);
static Interval sum_partial_pure_heights (Grob *me, int, int);