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CSC 236               Tutorial Exercises for Week 11              Fall 2007
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A.  For each regular expression R below, state whether or not the string
    010 belongs to L(R), and why.
     -  (e+1)0*1*0
     -  0(11)*0
     -  (e+0)(1*1*)*(0+1)
     -  (0*1*)*
     -  (0+1)(0*+1*)

B.  For each language L_i below, give a reg.exp. R_i such that L(R_i) = L_i
    and a F.S.A. A_i such that L(A_i) = L_i.  Briefly explain why your
    answers are correct.
     -  L_1 = { s in {a,b}* : s contains the substring bb }
     -  L_2 = { s in {a,b}* : s does not contain the substring bb }
     -  L_3 = { s in {a,b}* : s contains the substring bb exactly once }