Hein is the fourth son of Piet Hein, the Danish scientist, mathematician, inventor, designer, author, and poet who wrote the famed Grooks poetry collections and invented the Superegg and the Soma cube. When he was 12 years old, Jotun proved the Soma cube's "Basalt Rock" construction impossible, which was published in the puzzle's instruction manual as "Jotun's Proof."[1]
Hein, J; Schierup, M. H., and Wiuf, C. Gene Genealogies, Variation and Evolution – A Primer in Coalescent Theory. Oxford University Press, 2005. ISBN0-19-852996-1.