*This week, Katie and Paul are blogging from the Heidelberg Laureate Forum – a week-long maths conference where current young researchers in maths and computer science can meet and hear talks by top-level prize-winning researchers. For more information about the HLF, visit the Heidelberg Laureate Forum website.*

Bad news: The Turing award winner and father of LaTeX thinks the proofs you (and everyone else) are writing are sloppy, non-rigorous and quite likely flat-out wrong. But there’s good news too: Sir Michael Atiyah is not quite so sure.