Mark Dickinson added the comment: Raymond: I don't think it's gratuitous. I'd be happy to replace the 'inverse' by 'area' if that's what people prefer. But "hyperbolic arc cosine" is just plain incorrect. (And the "in radians" bit is utterly nonsensical.) ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21902> _______________________________________