Reverses the most recent
Shortcut menu: With
no commands active and no objects selected, right-click in the drawing
area and click Undo.
can enter u as many times as you wish, backing
up one step at a time, until the drawing is as it was when you began
the current editing session.
When an operation cannot be undone, the command
name is displayed but no action is performed. Operations external
to the current drawing, such as plotting or writing to a file, cannot
If you changed modes or used transparent commands
during a command, their effects are undone, along with the effects
of the main command.
You can also press Ctrl+Z to undo.
The U command is equivalent to entering undo