0 votes 0 votes RAJESHWAR YADAV asked Nov 27, 2016 RAJESHWAR YADAV 190 views answer comment Share Follow See 1 comment See all 1 1 comment reply santhoshdevulapally commented Nov 29, 2016 reply Follow Share i think one of the string given in the options is derived from $X_{1}\cup X_{2}$. consider one by one and verify 0 votes 0 votes Please log in or register to add a comment.