The recent spate of evictions of Roma communities across Europe reflect a historical discrimination against those considered as illegitimate outsiders. At a time when walls are going up across the world, the issue of who belongs and who is denied access to certain spaces is evermore prescient, and in need of critical attention.

By drawing several straight lines that cross one point on a piece of paper, we arrive at one of the most fascinating mathematical theories: Committee theory not only has a number of practical applications like pattern recognition – a central branch of machine learning – but also searches for collective solutions to problems that have no familiar solution at all.