- exception OutOfRange;
exception OutOfRange
- fun fibo(0)=1 | fibo(1)=1 | fibo(n)=if n<0 then raise OutOfRange else 
fibo(n-1
)+fibo(n-2);
val fibo = fn : int -> int

- fibo(~1);

uncaught exception OutOfRange
  raised at: stdIn:25.55-25.65
- fibo(0);
val it = 1 : int
- fibo(1);
val it = 1 : int
- fibo(7);
val it = 21 : int
-