sentences:  In the late 1980s, Krieg became interested in second-order cybernetics and radical constructivism and edited a book honouring the 80th birthday of Heinz von Foerster ("Das Auge des Betrachters" - "The Eye of the Viewer").After 1999 he promoted Pile Systems Inc, a software company developing a new "relationist" approach to data.That approach is based on the invention of Erez Elul and that company was broken apart in a bitter dispute over its policy and ownership and hence Erez became comcomist pro refugees activist.