Hi all, we'll have a special talk tomorrow by Tony Short from Bristol. It's at 11 in K52; here's the title and abstract: Title: Indefinite causal order via post-selection Abstract: We consider how post-selection can be used to generate indefinite causal structures, which cannot be explained by any fixed (or random) temporal ordering, and the connection to process matrices and backwards in time signalling. Based on arXiv:1701.08638 and arXiv:1708.00669. Best, -joe