3. Show that the following languages are context-free: (a) {a*bmc" | k, m, n not all equal) (b) {xcy |x.y fa, b}* and rev(x) is a substring of y} In other words: strings that contain a single c character, where the part of the string occurring before c appears reversed somewhere after the c Example: aaabbcabababbbaaabba is in the language