1 votes 1 votes someone please explain option (C) and option (D)....... (ANSWER IS B). newdreamz a1-z0 asked Oct 15, 2018 newdreamz a1-z0 418 views answer comment Share Follow See all 7 Comments See all 7 7 Comments reply Mk Utkarsh commented Oct 15, 2018 reply Follow Share https://cs.stackexchange.com/questions/19151/is-the-complement-of-ww-context-free This can help you for D and https://gateoverflow.in/203733/complement-of-cfl for C 1 votes 1 votes newdreamz a1-z0 commented Oct 15, 2018 reply Follow Share 1 more question .. IF L1 IS REGULAR LANGUAGE AND L2 IS DCFL BUT NOT REGULAR THEN WHAT WILL BE (L1 INTERSECTION L2)? 0 votes 0 votes amitqy commented Oct 15, 2018 i moved by Mk Utkarsh Oct 15, 2018 reply Follow Share is ww^r CFL. If yes, how? 0 votes 0 votes Mk Utkarsh commented Oct 15, 2018 reply Follow Share $\Sigma^* \ \cap a^n b^n = a^n b^n$ $ab \ \cap a^n b^n = ab$ i don't know how to prove it but it will be DCFL. 1 votes 1 votes Deepak Poonia commented Oct 15, 2018 reply Follow Share IF L1 IS REGULAR LANGUAGE AND L2 IS DCFL BUT NOT REGULAR THEN WHAT WILL BE (L1 INTERSECTION L2)? https://math.stackexchange.com/questions/1541057/dcfl-are-closed-under-intersection-with-regular-languages is ww^r CFL. If yes, how? $L = \left \{ ww^r | w \in \Sigma^+ \right \}$ is a context-free language $S \rightarrow aSa | bSb | aa | bb$ $L = \left \{ ww^r | w \in \Sigma^* \right \}$ is a context-free language $S \rightarrow aSa | bSb | \in $ 1 votes 1 votes amitqy commented Oct 16, 2018 reply Follow Share yes it is CFL.How to draw its PDA? There is no center available. 0 votes 0 votes garimanand commented Oct 23, 2018 reply Follow Share in option C complement of WW^r which is CFL Acceptable by NPDA . and cfl does not closed under closed under complementation so why C is not answer C is also CSL but Not CFL 0 votes 0 votes Please log in or register to add a comment.