Write russian peasant algorithm for fast exponentiation method using Ocaml language in tail recursion.

The attached image is NOT in tail recursive function.

*function that returns a boolean. # et even n- (n mod 2) -0;; two input args # et rec rpe base' powe r if base0 then 0 else if power 0 then 1 else if (odd power) then base (rpe base (power - 1)) else let tmp(rpe base (power/2)) in tmp * tmp;; val rpe : int -> int -> int -