Li-Fan Chen says to OwO /js@mmis_js_bot let Y = (F) => (x) => F((y)=> (x(x))(y)))((x) => F( (y) => (x(x))(y)) let fac = let fac = f => x =>( (x<=1)? 1 : x*f(x-1)) console.log(Y(fac)(3))