With this work phase (1969-72), a logical and automatic construction of pictures is introduced into my work. For the first time algorithms (rules with a beginning and an ending) are used to calculate the images. My consequent thinking is rendered visible through computer programs I wrote. The resulting drawings were realized by a computer controlled drawing machine (plotter). With a choice of different line characteristics, an alphabet of arbitrary generated elements is created. Individual algorithms are invented for each work from which all forms and structures are solely generated. The algorithms are built from imposed as well as from random selection principles which I called “aesthetical-filters”.