0 votes 0 votes I AM 100% SURE THAT MY ANSWER IS CORRECT , ISN'T IT!! IT SHOULD BE "A" , RIGHT?? Gate Fever asked Oct 18, 2018 Gate Fever 572 views answer comment Share Follow See all 9 Comments See all 9 9 Comments reply Show 6 previous comments Gate Fever commented Oct 18, 2018 reply Follow Share L1=L2 MEANS L1-L2= PHI AND L2-L1=PHI that is (L1 ⋂ L2' =∮ )⋃ ( L2 ⋂ L1' =∮) NOW DCFL ARE NOT CLOSED ON INTERSECTION! HOW CAN THIS BE DECIDABLE! I DONT THINK ANY OF THE ABOVE 4 OPERATIONS ARE DECIDABLE!! 0 votes 0 votes Mk Utkarsh commented Oct 18, 2018 reply Follow Share https://gatecse.in/grammar-decidable-and-undecidable-problems/ 0 votes 0 votes Gate Fever commented Oct 18, 2018 reply Follow Share That's ok. But can u prove my proof is wrong. 0 votes 0 votes Please log in or register to add a comment.