Create a CFG for the following languages:
a) $\{a^m b^m ... a^k b^k \mid \text{for $m, ..., k$ is positive integers}\}$
b) $\{w ∈ \{a,b\}^* \mid \text{$w$ contains more $a$ than $b$}\}$
c) $\{w ∈ \{a,b\}^* \mid \text{$w$ is a palindrome}\}$
My answers:
a) $S \to aSb \mid \varepsilon$
b) $S \to aSb \mid A A \mid aA \mid \varepsilon$
c) $S \to aSa \mid bSb \mid \varepsilon$
According to the answer sheet these are wrong. So how am I supposed to think here? Can you give me some tips how to solve it?
(a) It is difficult to understand your question. What is the meaning of the suspension points?
(b) How do you obtain $baa$ with your solution?
(c) How do you obtain $aba$ with your solution?