G2

; G2 Factorial and Fibonacci Example
; Demonstrates G2 recursive procedures by Gensym Corporation

procedure factorial [n: integer] -> integer
  begin
    if n <= 1 then return 1
    return n * factorial[n - 1]
  end

procedure fibonacci [n: integer] -> integer
  begin
    if n <= 0 then return 0
    if n = 1 then return 1
    return fibonacci[n - 1] + fibonacci[n - 2]
  end

procedure run-math-demo []
  begin
    local i: integer
    format t "Factorials:~%"
    for i from 1 to 10 do
      format t "  ~a! = ~a~%" i, factorial[i]
    end
    format t "~%Fibonacci:~%"
    for i from 0 to 10 do
      format t "  fib(~a) = ~a~%" i, fibonacci[i]
    end
  end