While running the SKETCH command, with the pen up
or down, enter e (Erase).
If the pen was
down, it moves up.
Move the cursor to the end of the line you drew last and then
move it back as far along the line as you want to erase.
To end the erasure and return to the SKETCH Command prompt,
enter p. To undo the erasure, enter
e.
If you want to
change the current viewport while sketching, make sure the pen is
up, all lines entered so far have been recorded, and Tablet mode is
off.