0 votes 0 votes closed with the note: doubt cleared according to me S2 should be correct. But answer given as none of them is correct. Please clear the doubt. Theory of Computation test-series theory-of-computation + – Ananya Jaiswal 1 asked Nov 1, 2018 • closed Nov 1, 2018 by Ananya Jaiswal 1 Ananya Jaiswal 1 444 views comment Share Follow See all 2 Comments See all 2 2 Comments reply Rishav Kumar Singh commented Nov 1, 2018 reply Follow Share I think it should be false because let L1= {bb} L2 ={b} then L1.L2 = bbb = L2.L1 0 votes 0 votes CS.user commented Jan 13, 2019 reply Follow Share Consider two language over $\sum =\{{a}\}$ where- L1= #of a divisible by 2 L3=#of a divisible by 3. Clearly L1 and L2 are two diff. language. But L1.L2=L2.L1. Is'nt it? So, S2 also False. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes if L1={a}, L2={aa} then concatenation is commutative so option S2 is wrong vtreddytkp answered Nov 1, 2018 • edited Nov 1, 2018 by vtreddytkp vtreddytkp comment Share Follow See all 3 Comments See all 3 3 Comments reply Ananya Jaiswal 1 commented Nov 1, 2018 reply Follow Share its given that we are concatenating 2 DIFFERENT language. in your example L1 and L2 are same. 0 votes 0 votes Shaik Masthan commented Nov 1, 2018 reply Follow Share L1 = {a,aa,aaa} and L2 = { a,aa} then S2 is False, isn't it ? 0 votes 0 votes Ananya Jaiswal 1 commented Nov 1, 2018 reply Follow Share yes. i understood now. it should be false 0 votes 0 votes Please log in or register to add a comment.