Figure 22.1 shows what happens when the Duration button for the Repetition Group shown selected in figure 21.1 is clicked: a message box with title Duration plus other statistics appears. The numbers in this message box are all in seconds.
Here, the Duration of this Repetition Group is 4 seconds, but it has the Potential to be approximately 5.77 seconds, which is also the duration of the Children of this Repetition Group — a single Chord Group in this case. Offset is the offset of this Repetition Group in its container (a Sequence box here), and it has the value zero (a Repetition Group placed directly inside a Sequence box will always be at offset zero, whereas if it were placed inside a Chord Group it may well not be). Last ofs is the offset of the start of the last sound of the last repetition.
The fact that the Duration is 4 seconds while the Potential and Children values are greater means that there will be some curtailment of the sound. In some situations we may want that, but here we do not. The reason that the duration is limited to 4 is explained if you go back to figure 19.1, where a duration of 4 was specified for the Sequence box that contains this Repetition Group.