Turtle graphics

Abstract

Twenty-five years ago Martin Gardner wrote an article in "Mathematical Games" of the Scientific American with the title Fantastic patterns traced by programmed "Worms" [Gar 1]. Later on these worms were called "turtles". These turtle graphics are well known from the LOGO-system [Ab/diS].These graphics are also vector graphics not made by setting absolute coordinates but by setting relative increments of distances and angles. With tiny APL2 idioms I have developed many 2D-graphics. It has happened in a short time in a normal manner and as a dialogue form. My top is " one-liner as eye liner "