recursive prog

[mcarthybn]

Hi,
I am very much puzzled to solve this problem .Though i am not from comp. science background but have passion to crack the algos.
Prob is ->
How do you prove the correctness of a recursive program? Prove the correctness the
following function which computes n’th Fibonacci number
function fib(n)
begin
if (n1) then
return (n)
else
return (fib(n-1)+fib(n-2))
end

So please help me on this problem .

[shabinesh]

i think it can be proved with mathematical induction