1 votes 1 votes I have read that T.M does not accept ε , but then in questions I have read T.M taking input ε ? Well, if T.M can't accept ε then why we are giving T.M the input ε ? Thank you! Theory of Computation theory-of-computation turing-machine self-doubt decidability + – iarnav asked Oct 17, 2017 iarnav 711 views answer comment Share Follow See all 9 Comments See all 9 9 Comments reply Show 6 previous comments iarnav commented Oct 19, 2017 reply Follow Share Thank you all, it makes sense now. Thanks. 0 votes 0 votes Shubhanshu commented Oct 19, 2017 reply Follow Share @Angkit ϵ is the empty string. A Turing machine accepts ϵ if the start state of its finite control is an accepting state. Is there any other way you know?? 0 votes 0 votes Arjun commented Oct 19, 2017 reply Follow Share He used "if" and not "iff" or else the problem would have become decidable :) 0 votes 0 votes Please log in or register to add a comment.