Stellproblemen (which means “set-problems”, and is purposely misspelled in German), is an artist book by Heimo Zobernig. Along with notions like alter ego, copy, dummy, imitation, mimicry, proxy, remake, substitution, and, of course, coincidence, the book addresses for the first time a central aspect of his work: the notion of repetition, which is inscribed into the very design of the book.