2. Let S = {a,b}. Let u = a'b2ab3 and v= b2ab be strings in E. Compute the following (a) uv and uvl. (b) vu and (vul. (c) cu. (d) veu. (e) uev. 3. Let be an alphabet. For any strings u, V E , prove that (a) uv = \u+ ul. (b) |uv| = |vul. 5. Let E = {a,b}. Write out three representative strings for each of the following language definitions (a) L = {a"b|m >0} (b) L= {a"b"|m>0, n >0} (c) L = {b}"ab"|m > 0, n >0} (d) L= {(ab)"m>0} (e) L = {aba4|m >0}