1 votes 1 votes For even no a's RE over {a,b} 1) (b*ab*ab*)* + b* 2) (b*ab*ab*)*.b* 3) both are equal? which one is correct? Theory of Computation theory-of-computation finite-automata regular-expression + – dyadav335 asked Aug 14, 2017 edited Aug 14, 2017 by dyadav335 dyadav335 2.3k views answer comment Share Follow See all 7 Comments See all 7 7 Comments reply Show 4 previous comments Shubhanshu commented Aug 14, 2017 reply Follow Share both are same and can be used for generating even no of a's. 1 votes 1 votes AnilGoudar commented Aug 15, 2017 reply Follow Share Yes Both are same, accepts the even number of a's but the second RE also tries to accept of any number of b's due to concatenation. Sry fr the wrong ans 0 votes 0 votes Sumit Singh Chauhan commented Aug 15, 2018 reply Follow Share Both are same. multiple expression are possible for any given language. 0 votes 0 votes Please log in or register to add a comment.
3 votes 3 votes $(b^*ab^*ab^*)^*+b^* \equiv (b^*ab^*ab^*)^*b^* \equiv b^*(b^*ab^*ab^*)^* \equiv b^*(ab^*ab^*)^* \equiv (b^*ab^*a)^*b^*$ Praveen Saini answered Aug 14, 2017 Praveen Saini comment Share Follow See all 0 reply Please log in or register to add a comment.