Merging Segments
When you merge segments, the selected segment is always concatenated with the segment to its right on the timeline. The In mark of the selected segment remains the In mark, and the Out mark of the right segment remains the Out mark of the new segment. If you merge segments across a gap, the gap between the two is overridden and integrated into the new segment. How the annotation is merged is defined by the Merge Rules you can set. See
Defining Merge Rules for Annotated Segments.
To merge segments:
1. Select the stratum in which you want to merge segments.
2. Select the segment you want to merge with the segment to its right.
3. Do one of the following:

Click the Pane menu and select Merge with next.

Right-click the segment and select Merge with next.
The segments are merged and the former gap is overridden.