Given a finite alphabet $\Sigma$ with more than one symbol, is $L = \{u u^R u : u \in \Sigma^*\}$ context-free? ($u^R$ is the reverse word of $u$)I tried to show it wasn't context-free by using the pumping lemma but I'm out of ideas.
Is $\{u u^R u : u \in \Sigma^*\}$ context-free?
formal languages;context free