Let L, L' be languages over = {0, 1}. Define the following languages: 1. prefix(L) = {w *| x = wy for some x L, y *}. This is the set of prefixes of strings in L. 2. suffix(L) = {w * | x = yw for some x L, y *}. The set of suffixes of strings in L. 3. L/L' = {w *| wx L for some x L'}. The right quotient of L by L'. 4. L^R = {w^R | w L}. w^R is the reverse of the string w. 5. Max(L) = {w L| if x != then wx ! L}.