A sequence of ranges to specify the repetition can also be used in a special group called repeating unit with repetition ranges.
Here the repetition range is "3,5-7". The repetition count for the included structure can be: 3,5,6 or 7.
Syntax of the repetition ranges
The repetition ranges consist of ranges and/or numbers separated by commas. E.g 3, 5-7
To draw a repeating unit with repetition ranges
Draw the structure.
Click the Group tool on the toolbar, and select the structure to be included in the range.
In the "Create Group" dialog window choose the type "Repeating unit with repetition ranges" from the "Type" list.
Set the repetition ranges.