- Thread starter
- #1
- Apr 13, 2013
- 3,844
Hello again!! 
I have also an other question.In order to show that the language $L_{1}=\{w \in \{a,b\}^{*}:w \neq a^{r}b^r, r \geq 0\}$ is context-free, could I use the language $L_{2}=\{w \in \{a,b\}^{*}:w=a^{r}b^{k},r \neq k\} $ ?Isn't it like that:$L_{1}=(\{b\}^{*} \cdot L_{2}) U (L_{2} \cdot \{a\}^{*}) $ ?
I have also an other question.In order to show that the language $L_{1}=\{w \in \{a,b\}^{*}:w \neq a^{r}b^r, r \geq 0\}$ is context-free, could I use the language $L_{2}=\{w \in \{a,b\}^{*}:w=a^{r}b^{k},r \neq k\} $ ?Isn't it like that:$L_{1}=(\{b\}^{*} \cdot L_{2}) U (L_{2} \cdot \{a\}^{*}) $ ?