The goal is to build some efficient binary arithmetic at the λ-calculus level, using one of its little dialects, lambdatalk, using nothing but two special forms, (lambda & def), no data or control structures - if then else doesn't exist - and an empty dictionary, at least for the main algorithms. For instance: fibonacci(100) = 354224848179261915075 factorial(22) = 1124000727777607680000<p>Note: Please, don’t be disoriented by the wiki page splitted in narrow columns lost in a wide format. Like any spreadsheet (Excel, ...) it can be comfortably consulted and edited on any screens, wide and as narrow as those of smartphones, just use zooms +/- or dblclicks, sliders and fingers, it's easy and safe. Thank you.