This book constitutes the refereed proceedings of the 15th Conference on Computability in Europe, CiE 2019, held in Durham, UK, in July 2019. The 20 revised full papers presented were carefully reviewed and selected from 35 submissions. In addition, this volume includes 7 invited papers. The conference CiE 2018 had the following six special sessions: computational neuroscience, history and philosophy of computing, lowness notions in computability, probabilistic programming and higher-order computation, smoothed and probabilistic analysis of algorithms, and transnite computations.

In October 2010, Ai Weiwei's Sunflower Seeds appeared in the Turbine Hall in the Tate Modern. Six months later, he was arrested in China and held for over two months in terrible conditions. The most famous living Chinese artist and activist, Ai Weiwei is a figure of extraordinary talent, courage and integrity. From the beginning of his career, he has spoken out against the world's greatest totalitarian regime, in part by creating some of the most beautiful and mysterious artworks of our age, works which have touched millions around the world. After Weiwei's release, Barnaby Martin dodged the secret police to interview him about his imprisonment and his intentions. Based on these interviews and Martin's own intimate connections with China, Hanging Man is an exploration of Ai Weiwei's life, art and activism. It is a rich picture of the man and his beliefs, what he is trying to communicate with his art, and of his campaign for democracy and accountability in China. It is a book about courage and hope found in the absence of freedom and justice. 'Hanging Man is the most detailed, comprehensive and eloquent English-language account of what happens these days to Chinese political prisoners . . . [an] invaluable book' Literary Review