Turtle and Observer Command
setpendown?-at `xcor ycor boolean` Sets the pendown state of the turtle `xcor` units in the x direction and `ycor` units in the y direction away from the caller to `boolean`. Examples: setpendown?-at 1 1 true sets the pendown state of the turtle one unit to the right and one unit above the caller to true. Related commands: pd pu pendown?-at setpendown?-of setpendown?-towards