Every regular language is a CFL(Context-Free Language)

We want to construct a regular expression for the language accepted by the following DFA: b а,b a ´a 92 Follow the general algorithm as seen in class and in our textbook to construct this regular expression. (In order to simplify grading, you don't need to simplify the regular expressions, and you should follow the state removal in the specified order.) 1. Construct a GNFA (in the special form described in the textbook and in class) equivalent to this DFA. 2. Remove the state q1 from this GNFA. 3. Remove the state q2 from this GNFA. 4. Remove the state qo from this GNFA.

Can you show Grammar for expressions consisting of digits and plus and minus signs?

Construct two PDA that recognizes the following language: 1. Every prefix contains at least as many a's as b's 2. The string contains the same number of a's and b's. Hint: To get the maximum number of points, use as few states and nonterminals as possible!