setxy  -- Command, two inputs.
     The two inputs must be numbers.  The turtle is moved to the  point  on
     the  screen  whose  x  (horizontal) coordinate is the first input, and
     whose y (vertical) coordinate is the second input.  The center of  the
     screen,  where  the  turtle starts, has both coordinates zero.  If the
     pen is down, this command draws a line.  This command applies only  to
     the display turtle.
