trying f#

gistfile1.fs

let rec factorial(n : int) (mem : bigint) =
    match n with
    | 0 | 1 -> mem
    | _ ->  factorial (n - 1) (mem * bigint(n))


let BigFactorial(numero,mesaje)=
    Async.FromContinuations(fun (cont,error,cancelation) ->
                                printfn "ha comenzado el proceso: %s" mesaje
                                factorial numero 1I |>ignore
                                printfn "ha terminado el proceso: %s ." mesaje
                                cont())

Async.RunSynchronously(async{
    printfn "comenzando"
    do! BigFactorial(100000,"100 mil")
    do! BigFactorial(500, "500")
    printfn "fin..."
})