Computer History Museum 2018 Fellow: Guido van Rossum(computerhistory.org)

    if the text returned of (display dialog "Username" default answer "") is userAns

    expect(true).to eq true

    def fib(n,x=[0,1]):
       for i in range(abs(n)-1): x=[x[1],sum(x)]
       return x[1]*pow(-1,abs(n)-1) if n<0 else x[1] if n else 0

    for i in range(-30,31): print fib(i),

    with Ada.Text_IO, Ada.Command_Line;
    procedure Fib is
        X: Positive := Positive'Value(Ada.Command_Line.Argument(1));

       function Fib(P: Positive) return Positive is
       begin
          if P <= 2 then
             return 1;
          else
             return Fib(P-1) + Fib(P-2);
          end if;
       end Fib;
 
    begin
       Ada.Text_IO.Put("Fibonacci(" & Integer'Image(X) & " ) = ");
       Ada.Text_IO.Put_Line(Integer'Image(Fib(X)));
    end Fib;

    on fib(n)
        if n < 1 then
            0
        else if n < 3 then
            1
        else
            fib(n - 2) + fib(n - 1)
        end if
    end fib

    FUNCTION itFib (n)
        n1 = 0
        n2 = 1
        FOR k = 1 TO ABS(n)
            sum = n1 + n2
            n1 = n2
            n2 = sum
        NEXT k
        IF n < 0 THEN
            itFib = n1 * ((-1) ^ ((-n) + 1))
        ELSE
            itFib = n1
        END IF
    END FUNCTION

    (defn fibs []
      (map first (iterate (fn [[a b]] [b (+ a b)]) [0 1])))

    fib_rec = (n) ->
      if n < 2 then n else fib_rec(n-1) + fib_rec(n-2)

    function FibonacciI(N: Word): UInt64;
    var
      Last, New: UInt64;
      I: Word;
    begin
      if N < 2 then
        Result := N
      else begin
        Last := 0;
        Result := 1;
        for I := 2 to N do
        begin
          New := Last + Result;
          Last := Result;
          Result := New;
        end;
      end;
    end;
 

    defmodule Fibonacci do
        def fib(0), do: 0
        def fib(1), do: 1
        def fib(n), do: fib(0, 1, n-2)
 
        def fib(_, prv, -1), do: prv
        def fib(prvprv, prv, n) do
            next = prv + prvprv
            fib(prv, next, n-1)
        end
    end
 
    IO.inspect Enum.map(0..10, fn i-> Fibonacci.fib(i) end)

    fibonacci : Int -> Int
    fibonacci n = if n < 2 then
            n
        else
            fibonacci(n - 2) + fibonacci(n - 1)

      FUNCTION IFIB(N)
      IF (N.EQ.0) THEN
        ITEMP0=0
      ELSE IF (N.EQ.1) THEN
        ITEMP0=1
      ELSE IF (N.GT.1) THEN
        ITEMP1=0
        ITEMP0=1
        DO 1 I=2,N
          ITEMP2=ITEMP1
          ITEMP1=ITEMP0
          ITEMP0=ITEMP1+ITEMP2
    1   CONTINUE
      ELSE
        ITEMP1=1
        ITEMP0=0
        DO 2 I=-1,N,-1
          ITEMP2=ITEMP1
          ITEMP1=ITEMP0
          ITEMP0=ITEMP2-ITEMP1
    2   CONTINUE
      END IF
      IFIB=ITEMP0
      END

    func fib(a int) int {
      if a < 2 {
        return a
      }
      return fib(a - 1) + fib(a - 2)
    }

    fib(n) = n < 2 ? n : fib(n-1) + fib(n-2)

    function fibs(n) 
      return n < 2 and n or fibs(n - 1) + fibs(n - 2) 
    end

    proc Fibonacci(n: int): auto =
      var fn = float64(n)
      var p: float64 = (1.0 + sqrt(5.0)) / 2.0
      var q: float64 = 1.0 / p
          return int64((pow(p, fn) + pow(q, fn)) / sqrt(5.0))