Slurs over system and frame breaks

Slurs automatically cross system breaks and frame breaks, appearing in two parts on either side of the break.

By default, the endpoints of slurs that cross system/frame breaks are positioned at least 1/2 space outside the outer staff line and at a suitable position based on the pitch contour of the phrase before/after the break, that is, indicating whether the phrase rises or falls after the break.

If multiple slurs cross the same system break or frame break, such as if a phrase split by a break contains nested slurs, the ends of the slurs are stacked automatically and spaced a minimum of 1/2 space apart vertically.

Figure 1. The end of a system showing the first slur part; the end on the right indicates a continuation to the next system.
Figure 2. The start of the next system showing the second slur part; the end on the left indicates a continuation from the previous system.