2. Let S = {a} be an alphabet. Compute the closure S. 3. Let S = {a,b,c} be an alphabet and let . denote concatenation. Compute v. ( w), where v = ab, w = bba, and s is the empty word. 4. Let S = {0,1} be an alphabet and let LC {0,1} be a language given in set-builder notation as L = {w {0,1}*|w = 01x, 2 {0,1}}. Show that w = 0110 is in L