On Dec 21, 2010, at 6:57 PM, austin seipp wrote: > https://gist.github.com/750279 I took Austins code and modified it to run on a Tree GADT which is parameterized by its shape: https://gist.github.com/752982 Would this count as a function mirror with proof that mirror (mirror x) == x? -- Sjoerd Visscher