MIRROR allows you to reflect geometry across a plane.

Indicate the method of transformation by choosing from the
following options:

MOVE - to apply the transformation directly to the 
selected entities. All non-geometric data relating 
to the entities is preserved.

COPY - to apply the transformation to copies of the 
selected entities. Copies are created on the active level
and retain the attributes of the original geometry. All 
non-geometric data relating to the entities is preserved.
You can create as many copies as you want in one 
operation. The transformation for a given copy is 
applied to the results of the previous copy.

JOIN - to apply the transformation to copies of the 
selected entities and create lines from join positions on
the original entities to corresponding positions on the
copies. The new joining entities are lines that assume 
all the current default line attributes. Coincident
positions generate only one joining entity.

Joined copies are created on the active level; all 
non-geometric data relating to the entities is preserved;
you can create as many copies as you want in one 
operation; the transformation for a given copy is applied 
to the results of the previous copy.

Select the entities desired to be mirrored, using a
Selection Menu option.

Define the mirroring plane by choosing from the following
options:

1 PT H - to define the plane perpendicular to the
construction plane, horizontal with respect to the
construction view, and containing a specified position.
Indicate the position, using a Position Menu option.

1 PT V - to define the plane perpendicular to the
construction plane, vertical with respect to the
construction view, and containing a specified position.
Indicate the position, using a Position Menu option.

2 POINTS - to define the plane perpendicular to the
construction plane and containing two specified positions.
Indicate the two positions, using a Position Menu option.

PLANE - to define the plane using the following options:
3PTS, PT/LINE, 2 LINES, VW/DEPTH, ENTITY.

If you chose MOVE, you can choose one of the following
options:

CONT - to continue transforming the selected entities.

UNDO - to reverse the move and return the geometry of the
selected entities to what it was before the move.
