3 votes 3 votes Which of the following regular expression identities are true ? (A) (r + s)* = r* s* (B) (r + s)* = r* + s* (C) (r + s)* = (r*s*)* (D) r* s* = r* + s* Theory of Computation regular-expression + – Sanjay Sharma asked Apr 13, 2016 Sanjay Sharma 16.0k views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply simran batra commented Sep 22, 2018 reply Follow Share D should be answer bcz c option 's lhs also generate sr which rhs is incapable to generate 0 votes 0 votes Sanjay Sharma commented Sep 22, 2018 reply Follow Share question is which one is correct 0 votes 0 votes Please log in or register to add a comment.
Best answer 11 votes 11 votes (r + s)* = (r*s*)* ManojK answered Apr 13, 2016 • selected Apr 13, 2016 by srestha ManojK comment Share Follow See all 2 Comments See all 2 2 Comments reply Pranav Madhani commented Dec 23, 2017 reply Follow Share need explaination..... 1 votes 1 votes Ajay Jadhav commented Dec 23, 2017 reply Follow Share Try generating strings from both sides RHS is capable of producing strings like LHS in option 3 only in first rsr is not generated by RHS In second RHS only produces rrrr.... or ssss..... which is not like LHS In fourth option RHS only creates rrrr.... or sssss unlike LHS (rrrrr...sssss...) 0 votes 0 votes Please log in or register to add a comment.
3 votes 3 votes c) (r+s)*=(r*s*)* Sanket_ answered Apr 14, 2016 Sanket_ comment Share Follow See 1 comment See all 1 1 comment reply SauravDeb commented Aug 14, 2020 reply Follow Share Can you please explain it? 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes Both b and c shravani answered Oct 12, 2016 shravani comment Share Follow See 1 comment See all 1 1 comment reply Sarthak Chauhan commented Sep 30, 2017 reply Follow Share not c 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes (r + s)* = (r* + s*)* = (r*s*)*=(r* + s)*=(r+s*)*=a*(ba*)*=b*(ab*)* Therfore option C will be right option for it. Paras Nath answered Dec 26, 2016 Paras Nath comment Share Follow See 1 comment See all 1 1 comment reply MIRIYALA JEEVAN KUMA commented Jan 23, 2018 reply Follow Share (r+s*)*=a*(ba*)*=b*(ab*)* is it right 0 votes 0 votes Please log in or register to add a comment.