sub fac(self$, n)
    if n > 1 then
        return n * execute(self$, self$, n - 1)
    else
        return 1
    end if
end sub

sub fib(self$, n)
    if n > 1 then
        return execute(self$, self$, n - 1) + execute(self$, self$, n - 2)
    else
        return n
    end if
end sub

sub test(name$)
    local i

    print name$, ": ";
    for i = 1 to 10
        print execute(name$, name$, i);
    next
    print
end sub

test("fac")
test("fib")