Symmetric Difference

Symmetric Difference is a special operation derived from basic Boolean logic. The resulting item geometry is the product of all geometries which do not intersect, or where more than two geometries from the test group intersect.

Where items overlap one another, you can delete the overlapping region leaving a hole. To do this use the Symmetric Difference analysis option.

With multiple levels of overlap, the areas are alternately deleted or left intact.

Select Analysis > Boolean Operations > Symmetric Difference.

1. Select the Polygon items (two or more).
   
2. Select Symmetric Difference.
3. The area of overlap is deleted and a MultiPolygon item is created as shown below:
   
4. If there are multiple areas of overlap, they are alternately deleted or left intact:
   

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