Fibonacci

gistfile1.sml

fun fib n = 
    let
        fun fib1 1 = (1, 0)
          | fib1 n = 
            let
                val (l, m) = fib1 (n-1)
            in 
                (l + m, l)
            end 
    in 
        #1 (fib1 n)
    end;