penup (pu)
Description:
Turtles pick up their pens, meaning that they no longer draw when they move.
Examples:
if pc-ahead = red [pu] commands the caller to lift its pen up and stop drawing as it moves if the patch ahead of it is red.
Related Commands:
pendown
pendown?
pendown?-of
pendown?-towards
setpendown?-at
setpendown?-of
setpendown?-towards