%ex2.3

\begin{enumerate}[label=(\alph*)]
	\item
		\textbf{Map function:} for every tuple t in R and for every tuple t in
		S, produce the key-value pair (t,t);\\
		\textbf{Reduce funtion:} Receives input of the form (t; [t, t, …, t])\\
	\item
		\textbf{Map function:} for every tuple t in R and for every tuple t in
		S, produce the key-value pair (t; ''R'') or (t; ''S''), respectively.\\
		\textbf{Reduce function:} Receives input of the form (t;
		[x_{1},…,x_{n}]), where each x_{i} is either the form of ''R'' or
		''S''.
		Outputs (t,t) if the input contains ''R'' but not ''S''.
		Outputs nothing otherwise.\\
\end{enumerate}
