RosettaCodeData/Task/Fibonacci-sequence/Seed7/fibonacci-sequence-1.seed7

const func integer: fib (in integer: number) is func
  result
    var integer: result is 1;
  begin
    if number > 2 then
      result := fib(pred(number)) + fib(number - 2);
    elsif number = 0 then
      result := 0;
    end if;
  end func;