DOUBLE allows you to break a selected entity (including
circles) into two or three separate entities, defined by
intersections with two other entities. The two outer
portions of the entity are created as two separate 
entities and are assigned the current attributes in 
effect.

Select the entity you want to break.

Select the first of two intersecting entities near 
the intersection point of the entity to be broken.

Select the second of the two entities in the same manner,
near the intersection point of the entity to be broken. 
The first reference entity can be selected again if it
intersects the entity to be broken at a different point.

The entity to be broken is redrawn as three separate
entities. The first of the three entities is on the 
outside of the first intersecting entity, and takes on the 
current attribute settings. The second entity lies between 
the two intersecting entities and keeps the original 
display status settings. The third is on the outside of 
the second intersecting entity and also reflects the 
current attribute settings.
