Write a tail$-$recursive Prolog procedure diff$2($L$,$ R$)$ to compute the following:$$L is a list of ordered pairs of the form $($a$,$ b$),$ where a and b are integers. R contains the result$$when we add all the u$\text{'}$s$,$ where u $=($b $-$ a$)$ for each of the ordered pairs in the list L$.$