ask_2012 (Systems Analysis)

38
ΑΣΚΗΣΕΙΣ ΓΙΑ ΚΑΝΟΝΙΚΕΣ ΓΛWΣΣΕΣ ΚΑΙ ΠΕΠΕΡΑΣΜΕΝΑ ΑΥΤΟΜΑΤΑ (1) L = a(a + b) * . Απ.: Λέξεις που αρχίζουν mε a. a a b (2) L =(a + b) * ab. Απ.: Λέξεις που τελειώνουν σε ab. a b b a a b (3) L =(a + b) * bb(a + b) * a. Απ.: Λέξεις mε δυο διαδοχικά b, δηλαδή, mε το bb, οι οποίες τελειώνουν σε a. b a a b b a a b (4) L =(a + ab) * . Απ.: Λέξεις χωρίς καθόλου διαδοχικά b, δηλαδή, χωρίς το bb, οι οποίες αρχίζουν mε a. a a b a 1

description

Algorithm and Systems Analysis

Transcript of ask_2012 (Systems Analysis)

  • (1) L = a(a+ b).

    pi.: pi a.

    a

    a

    b

    (2) L = (a+ b)ab.

    pi.: pi ab.

    a

    b

    b

    a

    a

    b

    (3) L = (a+ b)bb(a+ b)a.

    pi.: b, , bb, pi a.

    b

    a

    a

    b

    b

    a

    a

    b

    (4) L = (a+ ab).

    pi.: b, , bb, pi a.

    a

    a

    b

    a

    1

  • (5) L = (+ b)(a+ ab).

    pi.: b, , bb.

    a b

    a

    b

    a

    (6) L = (a+ bab).

    pi.: pi b.

    b

    b

    a a

    (7) pi a a.

    pi.: L = a(a+ b) + (a+ b)a.

    a b

    a

    b

    b a

    a

    b

    2

  • (8) pi a a, .

    pi.: L = a(a+ b)b+ b(a+ b)a.

    a b

    a b ab

    a

    b

    b

    a

    (9) pi .

    pi.: L = a(a+ b)a+ b(a+ b)b+ a+ b.

    a b

    a b ab

    a

    b

    b

    a

    (10) = {a, b, c}, pi a, pi b ( pi) c, , cc.

    pi.: L = a(a+ c)b(a+ c)b(a+ c)cc.

    a b b

    c

    c

    a

    a

    a+ c a+ c a c

    3

  • (11) = {a, b, c}, pi b pi pi c.

    pi.: L =((a+ c)bc+

    )(a+ c).

    b

    c

    b

    a

    a+ c c

    (12) pi , , pi bab bb. ( babb bab bb, , ,, 2 , pi babb ...)

    pi.:

    a aa

    b

    a

    b

    b

    a a

    a

    b

    a

    (13) pi .

    pi.: L =((a+ b)(a+ b)

    )= (aa+ ab+ ba+ bb).

    a+ b

    a+ b

    (14) pi pi .

    pi.: L = (a+ b)((a+ b)(a+ b)

    )= (a+ b)(aa+ ab+ ba+ bb).

    a+ b

    a+ b

    4

  • (15) = {a, b, c}, 3.

    pi.: L = (a+ b+ c)(a+ b+ c)(a+ b+ c) = (a+ b+ c)3.

    a+ b+ c a+ b+ c a+ b+ c

    (16) = {a, b, c}, 3.

    pi.: L = + (a+ b+ c) + (a+ b+ c)2.

    a+ b+ c a+ b+ c

    (17) = {a, b, c}, 3.pi.: L = (a+ b+ c)3(a+ b+ c)+.

    a+ b+ c a+ b+ c a+ b+ c a+ b+ c

    a+ b+ c

    (18) pi pi ab .

    pi.: L = (a + b)ab(a+ b).

    a b

    b a a+ b

    (19) pi pi ab .

    pi.: L = (a + b)ab(a + b)ab(a+ b).

    a b a b

    b a b a a+ b

    5

  • (20) a, , aa.

    pi.: L = (b+ ab)(+ a).

    a

    b

    b

    (21) a , , pi pi aa .

    pi.: L = (b+ ab)aa(b+ ab).

    a

    b

    b

    a

    b

    a

    b

    (22) a , , pi pi aa .

    pi.: L = (b+ ab)aa(a+ b+(ab)aa

    )(a+ b).

    a

    b

    b

    a

    a

    b

    b

    a

    b

    a

    a+ b

    6

  • (23) a b, , pi pi aa bb.

    pi.: L = (a+ b)aa(a+ b)bb(a+ b) + (a+ b)bb(a+ b)aa(a+ b).

    a

    b

    b

    a

    a

    ba

    b

    a

    b

    a

    b

    a

    b

    a+ b

    (24) pi pi ab ba.

    pi.: L = (bab+a+ aba+b)(a+ b).

    a

    b

    b

    a

    a

    b

    a

    b

    b

    a

    b

    a

    a

    b

    a+ b

    (25) = {a, b, c}, a, , aa.

    pi.: L = (b+ c+ ab+ ac)(+ a).

    a

    b+ c

    b+ c

    7

  • (26) = {a, b, c}, a, , pi pi aa.

    pi.: L =(b+ c+ a(b+ c)

    )aa(a+ b+ c).

    a

    b+ c

    b+ c

    a

    a+ b+ c

    (27) pi pi pi b, , pi pi bb.

    pi.: L =(a(ba)a

    ))(abb+ bb(a+ b)

    )((a+ b)(a+ b)

    ).

    b

    ab

    a+ b

    a+ b

    a a

    b

    a

    b

    a+ b

    a+ b

    (28) = {a, b, c}, pi pi a.

    pi.: L =((b+ c)(b+ c)

    )a(b+ c)

    ((b+ c)(b+ c)

    )+ (b+ c)

    ((b+ c)(b+ c)

    )a((b+ c)(b+ c)

    ).

    a

    b+ c

    b+ c

    b+ c b+ c

    a

    b+ c

    b+ c

    8

  • (29) pi a, , pi aaa.

    pi.: L = b(a+ b) + ab(a+ b) + aab(a+ b) = (+ a+ aa)b(a+ b).

    a a

    bb

    b

    a+ b

    (30) a, , aaa.

    pi.: L = (b+ ab+ aab).

    a

    b

    a

    b

    b

    (31) aba.

    pi.: L =(abb+a

    )+ a + b + ab + ba.

    b

    a a b

    b b

    a

    a b

    9

  • (32) pi a (pi na) pi 3.

    pi.: L = b(ababab).

    a

    a

    a

    bb

    b

    (33) nb < na 2.

    pi.: L = L0 + L1, pi L0 pi pi na = 2 nb = 0 1 L1 pina = 1 nb = 0. , : L0 = aa+ baa+ aba+ aab L1 = a.

    a a

    b

    a a

    b b

    (34) = {a, b, c}, nb + nc = 3.

    pi.: L = L0 + L1 + L2 + L3, pi L0 pi pi nb = 3 nc = 0, L1 pi nb = 2 nc = 1, L2 pi nb = 1 nc = 2 L3 pi nb = 0 nc = 3., : L0 = abababa, L1 = ababaca + abacaba + acababa, L2 =acacaba + acabaca + abacaca L3 = acacaca.

    c

    c

    b+ c

    b+ c

    b+ cc

    b

    b

    ba

    a a

    a a

    a a

    10

  • (35) pi a b pi pi .

    pi.: L = (b+ ab+ ba+ aba).

    a b

    a

    b

    a

    b

    b

    (36) pi 4 pipi :

    q0 q1

    q2q3

    a

    a

    bb

    a

    a

    b b

    pi.:

    q0 na = nb = . q1 na = pi nb = . q2 na = pi nb = pi. q3 na = nb = pi.

    pipi, pi pi- . .., pipi q3:

    q0 q1

    q2q3

    a

    a

    bb

    a

    a

    b b

    q1 pipi :

    11

  • q0 q2 q3

    ab

    ba

    a

    a

    b

    b

    aa bb

    pi pi q2 pipi :

    q0 q3

    b+ ab(bb)a

    b+ a(bb)ba

    aa+ ab(bb)ba a(bb)a

    , pi, ( na = pi nb =pi) :

    L =(aa+ab(bb)ba

    )(b+ab(bb)a

    )((a(bb)a

    )(b+a(bb)ba

    )(aa+ab(bb)ba

    )(b+ab(bb)a

    )).

    (37) pi 3 pipi :

    q0

    q1

    q2

    a

    b

    a

    b

    a

    b

    pi.:

    q0 na nb = 0 mod 3. q1 na nb = 1 mod 3 nb na = 2 mod 3. q2 na nb = 2 mod 3 nb na = 1 mod 3.

    12

  • (38) pi 4 pipi :

    q0 q1

    q2q3

    a

    b

    ab

    a

    b

    a b

    pi.:

    q0 na nb = 0 mod 4. q1 na nb = 1 mod 4 nb na = 3 mod 4. q2 |na nb| = 2 mod 4. q3 na nb = 3 mod 4 nb na = 1 mod 4.

    (39) pi 9 pipi :

    q0 q1 q2

    q3 q4 q5

    q6 q7 q8

    b b

    b

    b

    b b

    a a a

    a a a

    b

    b

    a a a

    b

    pi.:

    q0 na = 0 mod 3 nb = 0 mod 3. q1 na = 0 mod 3 nb = 1 mod 3. q2 na = 0 mod 3 nb = 2 mod 3. q3 na = 1 mod 3 nb = 0 mod 3. q4 na = 1 mod 3 nb = 1 mod 3. q5 na = 1 mod 3 nb = 2 mod 3. q6 na = 2 mod 3 nb = 0 mod 3. q7 na = 2 mod 3 nb = 1 mod 3. q8 na = 2 mod 3 nb = 2 mod 3.

    13

  • (40) , (i) ( {a, b}), pi na = 1 mod 3 nb = 2 mod 3.

    pi.: pipi pi- . pi pi pi pi pi.

    (0) pi :

    q0 q1 q2 q3 q4 q5 q6 q7 q8q0 b a

    q1 b a

    q2 b a

    q3 b a

    q4 b a

    q5 b a

    q6 a b

    q7 a b

    q8 a b

    (1) pi q8:

    q0 q1 q2 q3 q4 q5 q6 q7 q8q0 b a

    q1 b a

    q2 b a

    q3 b a

    q4 b a

    q5 aa b ab

    q6 a b

    q7 a ba bb

    q8

    (2) pi q7:

    q0 q1 q2 q3 q4 q5 q6 q7 q8q0 b a

    q1 b a

    q2 b a

    q3 b a

    q4 aa aba b abb

    q5 aa b ab

    q6 a ba bba bbb

    q7q8

    14

  • (3) pi q6:

    q0 q1 q2 q3 q4 q5 q6 q7 q8q0 b a

    q1 b a

    q2 b a

    q3 a(bbb)a a(bbb)ba a(bbb)bba b

    q4 abb(bbb)a aa+ abb(bbb)ba aba+ abb(bbb)bba b

    q5 ab(bbb)a ab(bbb)ba aa+ ab(bbb)bba b

    q6q7q8

    (4) pi q4:

    q0 q1 q2 q3 q4 q5 q6 q7 q8q0 b a

    q1 aabb(bbb)a aaa+aabb(bbb)ba b+ aaba+

    aabb(bbb)bbaq2 b a

    q3a(bbb)a+babb(bbb)a

    a(bbb)ba+ baa+babb(bbb)ba

    a(bbb)bba+baba+

    babb(bbb)bbaq4q5 ab(bbb)

    a ab(bbb)ba aa+ ab(bbb)bba bq6q7q8

    (5) pi q3:

    q0 q1 q2 q5

    q0 aa(bbb)a+ababb(bbb)a b+ aa(bbb)

    ba+ abaa+ababb(bbb)ba

    aa(bbb)bba+ ababa+ababb(bbb)bba

    q1 aabb(bbb)a aaa+ aabb(bbb)ba b+aaba+aabb(bbb)bba

    q2 b a

    q5ab(bbb)a+ ba(bbb)a+

    bbabb(bbb)aab(bbb)ba+ba(bbb)ba+bbaa+ bbabb(bbb)ba

    aa+ ab(bbb)bba+ba(bbb)bba+ bbaba+

    bbabb(bbb)bba

    15

  • (6) pi q2:

    q0 q1 q5

    q0

    aa(bbb)a+ ababb(bbb)a+aa(bbb)bbab+ ababab+

    ababb(bbb)bbab

    b+ aa(bbb)ba+ abaa+ababb(bbb)ba

    aa(bbb)bbaa+ ababaa+ababb(bbb)bbaa

    q1aabb(bbb)a+ bb+ aabab+

    aabb(bbb)bbab aaa+ aabb(bbb)ba ba+ aabaa+ aabb(bbb)bbaa

    q5

    ab(bbb)a+ ba(bbb)a+bbabb(bbb)a+ aab+

    ab(bbb)bbab+ ba(bbb)bbab+bbabab+ bbabb(bbb)bbab

    ab(bbb)ba+ ba(bbb)ba+bbaa+ bbabb(bbb)ba

    aaa+ ab(bbb)bbaa+ba(bbb)bbaa+ bbabaa+

    bbabb(bbb)bbaa

    (7) pi q1:

    q0 q5

    q0

    (b+ aa(bbb)ba+ abaa+

    ababb(bbb)ba)(aa(bbb)a+ ababb(bbb)a+

    aa(bbb)bbab+ ababab+ababb(bbb)bbab

    )(aabb(bbb)a+ bb+ aabab+

    aabb(bbb)bbab)

    (b+ aa(bbb)ba+ abaa+

    ababb(bbb)ba)(aa(bbb)a+ ababb(bbb)a+

    aa(bbb)bbab+ ababab+ababb(bbb)bbab

    )(aa(bbb)bbaa+ ababaa+

    ababb(bbb)bbaa)

    q5

    (ab(bbb)ba+ ba(bbb)ba+ bbaa+

    bbabb(bbb)ba)(aa(bbb)a+ ababb(bbb)a+

    aa(bbb)bbab+ ababab+ababb(bbb)bbab

    )(aabb(bbb)a+ bb+ aabab+

    aabb(bbb)bbab)

    (ab(bbb)ba+ ba(bbb)ba+ bbaa+

    bbabb(bbb)ba)(aa(bbb)a+ ababb(bbb)a+

    aa(bbb)bbab+ ababab+ababb(bbb)bbab

    )(aa(bbb)bbaa+ ababaa+

    ababb(bbb)bbaa)

    , pi, pipi pipi (pi Aij pi 2 2):

    q0 q5

    A12

    A21

    A11 A22

    pi, :

    L = (A11)A12

    ((A22)

    A21(A11)A12).

    16

  • (41) :

    (i) na 1 nb = 2.(ii) na 2 nb 2.(iii) na 4 nb 2.

    pi. (i):

    q0 q1

    q2 q3

    q4 q5

    a

    a

    a

    b b

    b b

    a

    a

    a

    pi. (ii):

    q0 q1 q2

    q3 q4 q5

    q6 q7 q8

    a a

    a a

    a a

    b b b

    b b b

    b

    b

    b

    17

  • pi. (iii):

    q0 q1 q2 q3 q4

    q5 q6 q7 q8 q9

    q10 q11 q12 q13 q14

    a a a a

    a a a a

    a a a a

    b b b b b

    b b b b b

    a a a a a

    18

  • pi :

    (1) S aSa | aBa,B bB | b.pi.: S

    n= anSan m= an(amBam)an k= an+mbkBan+m an+mbk+1an+m. ,

    L = {aibjai: i 0, j > 0}.(2) S aSdd |A,A bAc | bc.

    pi.: Sn

    = anS(dd)n anA(dd)n m= an(bmAcm)(dd)n anbmbccm(dd)n =anbm+1cm+1(dd)n. , L = {aibjcjd2i: i 0, j > 0}.

    (3) S aSb | aSbb | .pi.: S

    n= anSbn m= an(amS(bb)m)bn an+mbn+2m. , L = {aibj: 0

    i j 2i}.(4) S abScB | ,B bB | b.

    pi.: Sn

    = (ab)nS(cB)n (ab)n(cB)n m= (ab)n(c(bmB))n (ab)n(cbm+1)n. , L = {(ab)i(cbj)i: i 0, j > 0}.

    pi :

    (5) L = {aibi: i 0}.pi.: S aSb | .

    (6) L = {(ab)i: i 0}.pi.: S abS | .

    (7) L = {aibi+1: i 0}.pi.: S aSb | b. S Bb,B aBb | pi.

    (8) L = {aib2i: i 0}.pi.: S aSbb | .

    (9) L = {aibj: i > 0, j 0}.pi.: S AB,A aA | a,B Bb | .

    (10) L = {ai+2bi: i 1}.pi.: S aSb | aaab.

    (11) L = {aibi3: i 3}.pi.: S aSb | aaa.

    (12) L = {aibj: j > i 0}.pi.: S aSb |Sb | b.

    (13) L = {aibj: i 6= j}.pi.: S S> |S aS>b | aS> | a, S< aS

  • (17) L = {aibj: 2i j 3i}.pi.: S aSbb | aSbbb | .

    (18) L = {a2ib3j: i, j 0}.pi.: S AB,A aaA | ,B Bbbb | .

    (19) L = {aibjck: i = j j k}.pi.: S S1C |AS2, S1 aS1b | , C Cc | ,A aA | , S2 bS2c |S2c | .

    (20) L = {aibjck: i = j j 6= k}.pi.: S S1C |AS3, S1 aS1b | , C Cc | ,A aA | , S3 S2 |S4,S2 bS2c |S2c | c, S4 bS4c | bS4 | b.

    (21) L = {aibjck: i 6= j j 6= k}.pi.: S S1C |AS3, S1 S5 |S6, S5 aS5b | aS5 | a, S6 aS6b |S6b | b, S3 S2 |S4,S2 bS2c |S2c | c, S4 bS4c | bS4 | b.

    (22) L = {aibjck: k = i+ j}.pi.: S aSc |S1, S1 bS1c | .

    (23) L = {aibjck: k 6= i+ j}.pi.: S S1 |S2, S1 aS1c |S3 | c, S3 bS3c |S3c | c,S2 AS4, A aA | , S4 aS4c |S5 | a, S5 bS5 | b.

    (24) L = {aibjck: i+ 2j = k}.pi.: S aSc |S1 | , S1 bS1cc | .

    (25) L = {aibjck: k = |i j|}.pi.: S S1 |S2S3, S1 aS1c |S2 | , S2 aS2b | , S3 bS3c | .

    (26) L = {aibick: i 0, k 3}.pi.: S S1C, S1 aS1b | , C Cc | ccc.

    (27) (i) L = {w (a+ b): |w| = }.(ii) L = {w (a+ b): |w| = pi}.pi.: pipi ( ):

    S T

    a+ b

    a+ b

    (i) S : S aT | bT | , T aS | bS.(ii) T : S aT | bT, T aS | bS | .

    (28) (i) L = {w (a+ b): |w| mod 3 = 0}.(ii) L = {w (a+ b): |w| mod 3 > 0}.(iii) L = {w (a+ b): |w| mod 3 6= |w| mod 2}.(iv) L = {w (a+ b): |w| mod 3 |w| mod 2}.pi.: pipi ( ):

    20

  • US Ta+ b

    a+ ba+ b

    (i) S : S (a+b)T | , T (a+b)U,U (a+b)S( S (a+ b)3S | ).

    (ii) T U : S (a + b)T, T (a +b)U | , U (a+ b)S | ( S (a+ b)T | (a+ b)2U, T (a+ b)3T | , U (a+ b)3U | ).

    (iii) , |w| mod 3 = |w| mod 2 |w| mod 6 = 0, pi |w|mod 3 6= |w| mod 2 |w| mod 6 = 1, 2, 3, 4 5. pi, pipi :

    S

    T U

    V

    X W

    a+ b

    a+ b

    a+ b

    a+ b

    a+ b

    a+ b

    , : S (a + b)T, T (a + b)U | , U (a + b)V | , V (a +b)W | ,W (a+ b)X | ,X (a+ b)S | .

    (iv) , |w| mod 3 |w| mod 2 |w| mod 6 6= 3, pi |w|mod 3 |w| mod 2 |w| mod 6 = 0, 1, 2 4, 5, 6. pi, pipi :

    S

    T U

    V

    X W

    a+ b

    a+ b

    a+ b

    a+ b

    a+ b

    a+ b

    , : S (a+ b)T | , T (a+ b)U | , U (a+ b)V | , V (a+ b)W,W (a+ b)X | ,X (a+ b)S | .

    (29) (i) L = {w (a+ b): na(w) = }.(ii) L = {w (a+ b): na(w) = pi}.(iii) L = {w (a+ b): na(w) = nb(w) = }.

    21

  • (iv) L = {w (a+ b): na(w) = nb(w) = pi}.pi.: pipi ( ):

    S T

    UV

    a

    a

    bb

    a

    a

    b b

    (i) S V : S aT | bV | , T aS | bU, U aV | bT, V aU | bS | . : pi na(w) na(ww) , , , na

    ((ww)

    ), pi pi na(bw) na(wb) , pi

    () : S AA | ,A AAA | bA |Ab | a.(ii) T U : S aT | bV, T

    aS | bU | , U aV | bT | , V aU | bS. : pi na(w) pi na(www) pi, , -, na

    (w(ww)

    )pi, pi pi na(bw) na(wb) pi,

    pi () : S AAA,A AAA | bA |Ab | a.(iii) S : S aT | bV | , T aS | bU, U

    aV | bT, V aU | bS.(iv) V : S aT | bV, T aS | bU, U

    aV | bT, V aU | bS | .

    (30) L = {w (a+ b+ c): abc pi w}.pi.: pipi ( ):

    U

    S T

    a

    c a

    b

    b

    b+ c

    a

    S, T U : S aU | bS | cS | , T aU | bS | , U aU | bT | cS | .

    22

  • (31) L = {w (a+ b): na(w) = 1}.pi.: pipi :

    S Ta

    b b

    T : S aT | bS, T bT | .(32) L = {w (a+ b): na(w) 1}.

    pi.: pi pi , pi pipi T(pi a T ): S aT | bS, T aT | bT | .

    (33) L = {w (a+ b): na(w) = 2}.pi.: pipi :

    S T Ua a

    b b b

    U : S aT | bS, T aU | bT, U bU | .(34) L = {w (a+ b): na(w) 2}.

    pi.: pi pi , pi pipi U(pi a U): S aT | bS, T aU | bT, U aU | bU | .

    (35) L = {w (a+ b): na(w) 3}.pi.: pipi :

    S T U Va a a

    b b b b

    S, T, U V : S aT | bS | , T aU | bT | , U aV | bU | , V bV | .

    (36) L = {w (a+ b): na(w) 3}.pi.: pipi :

    S T U Va a a

    b b b a+ b

    S, T, U V : S aT | bS, T aU | bT, U aV | bU, V aV | bV | .

    23

  • (37) L = {w (a+ b): na(w) = nb(w)}.pi.: pi w L w1w2 L, w1, w2 L, awb L bwa L, : S SS | aSb | bSa | .

    (38) L = {w (a+ b): na(w) = nb(w) + 1}.pi.: S0 pi pi a b(pi pi ), : S S0aS0, S0 S0S0 | aS0b | bS0a | .

    (39) L = {w (a+ b): na(w) > nb(w)}.pi.: S0 pi , :S S0AS0, S0 S0S0 | aS0b | bS0a | ,A aA | a.

    (40) L = {w (a+ b): nb(w) na(w)}.pi.: , pi pi, : S SS | aSb | bSa | bS | .

    (41) L = {w (a+ b): na(w) = 2nb(w)}.pi.: pi , pi , aab, aba baa, : S SS | aSaSb | aSbSa | bSaSa | .

    (42) L = {w (a+ b): na(w) = 2nb(w) + 1}.pi.: S2 pi pi a pi pi b (pi pi ), : S S2aS2, S2 S2S2 | aS2aS2b | aS2bS2a | bS2aS2a | .

    (43) L = {w (a+ b): na(w) = 2nb(w) 1}.pi.: , pi na(w) = 2nb(w)1 na(w)1 = 2(nb(w)1), pi , w L, a b pi pi pi w, , pipi , pi a pi pi b. pipi, a b, , ab ba. pi,pi pi , pi a pi pi b, pi ab ba, L. pi a pi pi b :S SS | aSaSb | aSbSa | bSaSa | . , S ab ba, pi () ab ba, S .pi, pipi pi pi pi a pi pi b S . pi S SS pi pipi : pi.., S aSaSb S Saab | aSab | aaSb | aabS ... pi, L :

    S Saab | aSab | aaSb | aabS |Saba | aSba | abSa | abaS |Sbaa | bSaa | baSa | baaS |ab | ba.

    24

  • (44) L = {w (a+ b): |na(w) nb(w)| = 1}.pi.: pi pi, : S S0aS0 |S0bS0, S0 S0S0 | aS0b | bS0a | .

    (45) L = {w (a+ b): w = wR}.pi.: , : S aSa | bSb | a | b | .

    (46) L = {wwR: w (a+ b)+}.pi.: , : S aSa | bSb | aa | bb.

    25

  • pi :

    (1) L = {aibi: i 0}.

    | , | ,

    a | , a | , b | ,

    (2) L = {aib2i: i 0}.

    | , | ,

    a | , a | , b | ,

    (3) L = {a2ibi: i 0}.

    | , | ,

    a | , a | , a | ,

    b | ,

    (4) L = {a2ib3i: i 1}.

    | , | ,

    a | , a | , a | ,

    b | ,

    26

  • (5) L = {aibj: i 6= j, i, j 0}.

    a | ,

    | , | ,

    | ,

    | ,

    | , b | ,

    | ,

    a | , a | , a | , b | ,

    a | , a | ,

    b | , b | ,

    (6) L = {aibj: 0 i j 2i}.

    | , | ,

    a | , a | , a | , a | , b | ,

    (7) L = {aibi: i 6= 0 mod 3}.

    a | , a | ,

    a | ,

    a | ,

    b | ,

    b | , b | ,

    | ,

    27

  • :

    b | 0, b | 1,

    | ,

    a | , 0a | 0, 10a | 1, 21a | 2, 02

    b | 0, b | 1, b | 2,

    (8) L = {ab(ab)ib(ba)i: i 0}.

    a | , b | , b | , b | , | ,

    a | , b | , b | , b | , a | ,

    (9) L = {anw : n 0, w (a+ b) |w| n}.

    | , | ,

    a | , a | , a+ b+ | ,

    (10) L = {w (a+ b): |w| }.

    | ,

    a+ b | , a+ b | ,

    28

  • (11) L = {w (a+ b): |w| pi}.

    | , | ,

    a+ b | , a+ b | ,

    (12) L = {w1aw2 (a+ b): |w1| |w2| }.

    a | ,

    a+ b | , a+ b | ,

    a+ b | , a+ b | ,

    | ,

    (13) L = {aibjci: i, j 0}.

    | , | , | ,

    a | , a | , b | , c | ,

    (14) L = {aibjck: i = j + k}.

    | , | , | ,

    a | , a | , b | , c | ,

    29

  • (15) L = {aibjck: j = i+ k}.

    | , | , | ,

    a | , a | ,

    b | , b | , b | , c | ,

    (16) L = {aibjck: k = i+ j}.

    | , | , | ,

    a | , a | ,

    b | , b | , c | ,

    (17) L = {a3bici: i 0}.

    a | , a | , a | , | , | ,

    a | , a | , c | ,

    (18) L = {aibjck: i = j j = k}.

    | ,

    | , | ,

    | ,

    | ,

    | , b | ,

    | ,

    a | , a | , b | , c | ,

    a | , b | , b | ,

    c | ,

    30

  • (19) L = {aibjck: j < i j < k}.

    | ,

    | ,

    | , | ,

    | ,

    | ,

    | ,

    a | ,

    a | , a | , b | ,

    c | ,

    b | , b | ,

    c | ,

    (20) L = {aibici: i 0}.

    | , ; , | , ; , | 1, ; 2,

    a | 1, 11; 2, 22a | 1, 11; 2, 22 b | 1, ; 2, 2 c | 1, 1; 2,

    (21) L = {aibicidi: i 0}.

    | , ; , | , ; , | , ; , | 1, ; 2,

    a | 1, 11; 2, 2a | 1, 11; 2, 2

    b | 1, ; 2, 22b | 1, ; 2, 22

    c | 1, 11; 2, c | 1, 11; 2, d | 1, ; 2, 2

    (22) L = {aibjcjdi: i, j 0}.

    | , ; , | , ; , | , ; , | 1, ; 2,

    a | 1, 11; 2, 2a | 1, 11; 2, 2

    b | 1, 1; 2, 22b | 1, 1; 2, 22 c | 1, 1; 2, d | 1, ; 2, 2

    31

  • (23) L = {a3ibjcid2j: i, j 0}.

    | , ; , | , ; , | , ; , | 1, ; 2,

    a3 | 1, 11; 2, 2a3 | 1, 11; 2, 2

    b | 1, 1; 2, 222b | 1, 1; 2, 222 c | 1, ; 2, 2 d | 1, 1; 2,

    (24) L = {w (a+ b)?: na(w) = nb(w)}.

    | ,

    a | , aa | a, aaa | b,

    b | , bb | b, bbb | a,

    (25) L = {w (a+ b)?: na(w) = nb(w) + 1}.

    na = nb na = nba | , | ,

    (26) L = {w (a+ b)?: na(w) nb(w) + 1}.

    na = nb na = nb | , a | , | , | , | ,

    a | , a | , a | ,

    (27) L = {w (a+ b)?: na(w) < nb(w)}.

    na = nb na = nb | , | , | , | , | ,

    b | , b | , b | ,

    32

  • (28) L = {w (a+ b)?: na(w) = 2nb(w)}.

    a | , aa | a, aa

    a | , a | a, a

    a | b, b | , bbb | b, bbbb | a,

    b | , bbb | b, bbbb | a,

    a | b, b | , bbb | b, bbbb | a,

    a | , a

    | ,

    | ,

    | ,

    (29) L = {w (a+ b)?: na(w) = 2nb(w) + 1}.

    na = 2nb

    na = 2nb

    na = 2nb

    na = 2nb | ,

    a | ,

    | ,

    a | ,

    | ,

    | ,

    a | ,

    33

  • (30) L = {w (a+ b)?: na(w) > 2nb(w)}.

    a | , aa | a, aa

    a | , a | a, a

    a | b, b | , bbb | b, bbbb | a,

    b | , bbb | b, bbbb | a,

    a | b, b | , bbb | b, bbbb | a,

    a | , a | a, | ,

    | a, | ,

    | a, | ,

    | ,

    | a,

    ():

    na = 2nb | a, | ,

    | ,

    | a,

    34

  • (31) L = {w (a+ b)?: na(w) = 3nb(w)}.

    E1

    E2

    E3

    E4

    E5

    E4

    E6

    | ,

    | ,

    | ,

    pi

    E1 : a | , aa | a, aa

    E2 : a | , a | a, a

    E3 : a | , a | a, a | ,

    E4 : b | , bbbb | b, bbbbb | a, a | b,

    E5 : b | , bbbb | b, bbbbb | a,

    E6 : a | , a

    35

  • (32) L = {w (a+ b)?: 2na(w) nb(w) 3na(w)}.

    E1

    E2

    E3

    E4

    E5

    E4

    E6

    | ,

    | ,

    | ,

    pi

    E1 : b | , bb | b, bb

    E2 : b | , b | b, b

    E3 : b | , b | b, b | ,

    E6 : b | , b

    E4 : b | , bbba | , aaaab | b, bbbba | a, aaaaaa | b, b | a,

    E5 : a | , aaaa | , aaaaa | a, aaaaa | a, aaaaa

    36

  • (33) L = {w (a+ b): |na(w) nb(w)| = 2}.

    a | , aa | a, aaa | b,

    b | , bb | b, bbb | a,

    a | , aa | a, aaa | b,

    b | , bb | b, bbb | a,

    a | , aa | a, aaa | b,

    b | , bb | b, bbb | a,

    a | ,

    b | ,

    a | ,

    b | ,

    | ,

    (34) L = {w (a+ b+ c)?: na(w) + nb(w) = nc(w)}.

    | ,

    a | , a | , a | , b | , b | , b | ,

    c | , c | , c | ,

    37

  • (35) L = {wwR: w (a+ b)?}.

    | , | ,

    a | , aa | a, aa

    b | , bb | b, bb

    a | a,

    b | b,

    (36) L = {wcwR: w (a+ b)?}.

    c | , | ,

    a | , aa | a, aa

    b | , bb | b, bb

    a | a,

    b | b,

    (37) L = {w (a+ b)?: w = wR}.pi.: , w = wR w = zzR w = zzR, pi z (a+ b) pi = a b. pi:

    | ,

    | , | ,

    a | , aa | a, aa

    b | , bb | b, bb

    a | a,

    b | b,

    38