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    - 4.1 -

    Chapter 4

    Problem Solutions

    4.1.

    w x y z f (a) (b) (c) (d) (e) (f) (g) (h)

    0 0 0 0 0 0 0 0 0 0 1 1 0

    0 0 0 1 0 0 1 0 0 0 1 1 0

    0 0 1 0 0 0 1 0 0 0 1 1 0

    0 0 1 1 0 0 1 0 0 0 0 1 0

    0 1 0 0 0 0 0 1 0 0 1 1 0

    0 1 0 1 1 0 1 1 0 0 1 1 1

    0 1 1 0 0 0 1 1 0 1 1 1 0

    0 1 1 1 0 0 1 1 0 0 0 1 0

    1 0 0 0 1 1 0 1 0 0 1 1 0

    1 0 0 1 1 0 1 1 1 0 1 1 0

    1 0 1 0 1 1 1 1 0 0 1 1 0

    1 0 1 1 1 0 1 1 1 0 1 1 0

    1 1 0 0 1 1 0 1 0 0 1 1 0

    1 1 0 1 0 0 1 1 0 0 1 0 0

    1 1 1 0 1 1 1 1 0 1 1 1 0

    1 1 1 1 0 0 1 1 0 0 1 0 0

    (a) wz-is an implicant since it implies f. However, neither

    the term w nor the term z-are implicants. Therefore, wz

    -

    is a prime implicant (1).

    (b) y+z is neither an implicant or implicate (6).

    (c) w+x is an implicate since it is implied by f. However,

    nether the term w nor the term x are implicates.

    Therefore, w+x is a prime implicate (3).

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    4.1. (continued)

    (d) wx-z is an implicant since it implies f. However, wx

    -z

    subsumes wx-which is also an implicant. Therefore, wx

    -z

    is an implicant, but not prime (2).

    (e) xyz-is neither an implicant or implicate (6).

    (f) w-+y-+z-is an implicate since it is implied by f.

    However, w-+y-+z-subsumes w+y

    -which is also an implicate.

    Therefore, w-+y-+z-

    is an implicate, but not prime (4).

    (g) w-+x-+z-is an implicate since it is implied by f.

    Furthermore, none of the sum terms w-+x-, w-+z-, and x-+z- are

    implicates. Therefore, w-+x-+z-is a prime implicate (3).

    (h) w-xy-z is an implicant since it implies f. However, none

    of the product terms w-xy-, w-xz, w

    -y-z, and xy

    -z are

    implicants. Therefore, w-xy-z is a prime implicant (1).

    4.2. (a) (b)

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    - 4.3 -

    4.2. (continued)

    (c) (d)

    (e) (f)

    4.3. The Karnaugh map is

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    4.3. (continued)

    The implicants correspond to all possible subcubes of 1-

    cells.

    one-cell subcubes

    (minterms)

    two-cell subcubes four-cell subcubes

    w-x-y-z-

    w-x-y-

    wy

    w-x-y-z w

    -x-z-

    w-x-yz-

    w-y-z

    w-xy-z wxy

    wx-yz-

    wx-y

    wx-yz x

    -yz-

    wxyz- wyz

    wxyz wyz-

    The prime implicants correspond to those subcubes which are

    not properly contained in some other subcube of 1-cells.

    The prime implicants are shown on the map. They are wy,w-x-y-, w

    -x-z-, w-y-z, and x

    -yz-.

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    4.4. (a)

    The prime implicants are xz, xy, y-z, yz

    -, x-z-, and x

    -y-.

    There are no essential prime implicants.

    (b)

    The prime implicants are w-x, xz, w

    -y-z, and wyz. All four

    prime implicants are essential as a result of the

    essential 1-cells indicated by asterisks.

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    - 4.6 -

    4.4. (continued)

    (c)

    The prime implicants are w-x-, w-z__, x-z-__, and x-y __. The

    essential prime implicants are underlined.

    (d)

    The prime implicants are y-z-, xy

    -__, x

    -z-

    __, and w-xz ___. The

    essential prime implicants are underlined.

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    4.5. (a)

    The prime implicates are x-+y+z and x+y

    -+z-. Both prime

    implicates are essential.

    (b)

    The prime implicates are w-+z, x+z, w+x+y

    -, and w

    -+x+y.

    All three prime implicates are essential.

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    - 4.8 -

    4.5. (continued)

    (c)

    The prime implicates are w-+x-, x-+z, and w-+y+z-. All three

    prime implicates are essential.

    (d)

    The prime implicates are x+z-

    ___, x-+y-+z_____, w

    -+x-+y-, and w

    -+y-+z-.

    The essential prime implicates are underlined.

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    - 4.10 -

    4.6. (continued)

    (c)

    Minimal sum:

    f = x-y-+ x-z + y

    -z + xyz

    -

    Minimal product:

    f = (x+y-+z)(x-+y+z)(x-+y-+z-)

    (d)

    Minimal sum:

    f = y-z-+ x-yz

    Minimal products:

    f = (y+z-)(y-+z)(x

    -+z-)

    f = (y+z-)(y-+z)(x

    -+y-)

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    - 4.11 -

    4.7. (a)

    Minimal sum:

    f = x + yz-

    Minimal product

    f = (x+y)(x+z-)

    (b)

    Minimal sum:

    f = x-+ y + z

    -

    Minimal product:

    f = x-+ y + z

    -

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    - 4.12 -

    4.7. (continued)

    (c)

    Minimal sum:

    f = x-z-+ yz

    Minimal product:

    f = (y+z-)(x-+z)

    (d)

    Minimal sum:

    f = y + x-z-

    Minimal product:

    f = (x-+y)(y+z

    -)

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    - 4.13 -

    4.8. (a)

    Minimal sum:

    f = xy + w-x-y- + x-y-z-

    Minimal products:

    f = (x-+y)(x+y

    -)(w-+y+z

    -)

    f = (x-+y)(x+y

    -)(w-+x+z

    -)

    (b)

    Minimal sum:

    f = xz-+ wz + x

    -yz

    Minimal products:

    f = (x+z)(w+x-+z-)(w+x+y)

    f = (x+z)(w+x-+z-)(w+y+z

    -)

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    4.8. (continued)

    (c)

    Minimal sum:

    f = wz + x-z + yz + w

    -xz-

    Minimal product:

    f = (w-+z)(x+z)(w+x

    -+y+z

    -)

    (d)

    Minimal sums:

    f = w-x-z-+ w-xy + wxz + wx

    -y-

    f = x-y-z-+ wy

    -z + xyz + w

    -yz-

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    - 4.15 -

    4.8. (continued)

    Minimal products:

    f = (w+x+z-)(w+x-+y)(w-+x-+z)(w-+x+y-)

    f = (x-+y+z)(w+y+z

    -)(x+y

    -+z-)(w-+y-+z)

    (e)

    Minimal sum:

    f = x-z- + yz + wy-

    Minimal products:

    f = (w+y+z-)(x

    -+y-+z)(w+x

    -+y)

    f = (w+y+z-)(x

    -+y-+z)(w+x

    -+z)

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    - 4.16 -

    4.8. (continued)

    (f)

    Minimal sum:

    f = w-x-+ y-z + wz + x

    -y

    Minimal product:

    f = (x-+z)(w+x

    -+y-)(w-+y+z)

    (g)

    Minimal sum:

    f = yz + x-z + xy

    -z-

    Minimal product:

    f = (x+z)(y-+z)(x

    -+y+z

    -)

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    - 4.17 -

    4.8. (continued)

    (h)

    Minimal sums:

    f = xy-+ xz + w

    -x-y + wyz

    -

    f = xy-+ wx + w

    -yz + x

    -yz-

    Minimal product:

    f = (x+y)(w-+x+z-)(w+x-+y-+z)

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    - 4.18 -

    4.8. (continued)

    (i)

    Minimal sum:

    f = wx- + x-z- + x-y- + w-y-z- + wy-z

    Minimal product:

    f = (x-+y-)(w+x

    -+z-)(w+y

    -+z-)(w-+x-+z)

    (j)

    Minimal sum:

    f = wx- + x-y + wyz + w-xz-

    Minimal products:

    f = (w+x+y)(w+x-+z-)(w-+x-+z)(w

    -+x-+y)

    f = (w+x+y)(w+x-+z-)(w-+x-+z)(x

    -+y+z

    -)

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    - 4.19 -

    4.9. (a)

    Minimal sums:

    f = w-x-z- + xyz + x-yz- + wx-y-z + w-xy

    f = w-x-z-+ xyz + x

    -yz-+ wx

    -y-z + w

    -yz-

    Minimal products:

    f = (x-+y)(w

    -+y+z)(x+y

    -+z-)(w-+x-+z)(w+x+z

    -)

    f = (x-+y)(w

    -+y+z)(x+y

    -+z-)(w-+x-+z)(w+y+z

    -)

    (b)

    Minimal sum:

    f = x-y-+ w-x + w

    -z-

    Minimal product:

    f = (w-+x-)(w-+y-)(x+y

    -+z-)

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    - 4.20 -

    4.9. (continued)

    (c)

    Minimal sum:

    f = x-y-z-+ xyz + w

    -xy + w

    -y-z

    Minimal products:

    f = (x+y-)(x-+y+z)(w

    -+y+z

    -)(w-+y-+z)

    f = (x+y-)(x-+y+z)(w

    -+y+z

    -)(w-+x-+z)

    (d)

    Minimal sum:

    f = y-z + w

    -z + x

    -z + w

    -xy-

    Minimal product:

    f = (x+z)(w-+z)(y

    -+z)(w

    -+x-+y-)

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    - 4.21 -

    4.9. (continued)

    (e)

    Minimal sums:

    f = xyz + xy-z-+ wy

    -z-+ w-x-y-z + wxy

    f = xyz + xy-z-+ wy

    -z-+ w-x-y-z + wxz

    -

    Minimal products:

    f = (x+y-)(x-+y+z

    -)(w+x+z)(w+y

    -+z)(w

    -+x+z

    -)

    f = (x+y-)(x-+y+z

    -)(w+x+z)(w+y

    -+z)(w

    -+y+z

    -)

    (f)

    Minimal sums:

    f = y-z-+ wz + w

    -y

    f = w-z-+ wy

    -+ yz

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    4.9. (continued)

    Minimal product:

    f = (w+y+z-)(w-+y-+z)

    (g)

    Minimal sum:

    f = wx + y-z + wy

    -+ xz

    Minimal product:

    f = (w+z)(x+y-)

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    - 4.23 -

    4.9. (continued)

    (h)

    Minimal sums:

    f = x-z-+ xz + wy

    -+ yz

    -

    f = x-z-+ xz + wy

    -+ xy

    Minimal product:

    f = (w+x+z-)(x+y

    -+z-)(w+x

    -+y+z)

    (i)

    Minimal sum:

    f = x-z + wz

    -

    Minimal product:

    f = (x-+z-)(w+z)

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    - 4.24 -

    4.9. (continued)

    (j)

    Minimal sums:

    f = x-y-+ w-y-

    + wxz + xyz-

    f = x-y-+ y-z + w

    -xz-+ wxy

    Minimal product:

    f = (x+y-)(w+y

    -+z-)(w-+x-+y+z)

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    - 4.25 -

    4.10. (a)

    The prime implicants are x-z-

    __, w-y-, xz __, and wy. The

    essential prime implicants are underlined.

    The prime implicates are x-+z and x+z

    -. Both prime

    implicates are essential.

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    - 4.26 -

    4.10. (continued)

    (b)

    The prime implicants are x, w-z, and wz-. All three

    prime implicants are essential.

    The prime implicates are w+z___, w-+x+z

    -_____, and w

    -+y-+z-. The

    essential prime implicates are underlined.

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    - 4.27 -

    4.10. (continued)

    (c)

    The prime implicants are wx__, yz-, w-y __, and xy. The

    essential prime implicants are underlined.

    The prime implicates are w+y___, x+y, w-+x ___, and x+z. The

    essential prime implicates are underlined.

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    - 4.28 -

    4.11. (a)

    Minimal sum:

    f = x-z- + xyz + w-y-z

    Minimal product:

    f = (x-+z)(w

    -+y+z

    -)(x+y

    -+z-)

    (b)

    Minimal sum:

    f = wy-+ x-yz-

    Minimal products:

    f = (w+y)(x-+y-)(w+z

    -)

    f = (w+y)(x-+y-)(y-+z-)

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    - 4.29 -

    4.11. (continued)

    (c)

    Minimal sum:

    f = y-z + xz + wz-

    Minimal product:

    f = (w+z)(x+y-+z-)

    (d)

    Minimal sums:

    f = wx + wz + yz

    f = wx + wz + xz

    f = wx + wz + xy

    Minimal product:

    f = (x+z)(w+y)

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    - 4.30 -

    4.11. (continued)

    (e)

    Minimal sums:

    f = x-z- + yz-

    f = x-z-+ w-z-

    Minimal products:

    f = z-(x-+y)

    f = z-(w-+x-)

    (f)

    Minimal sum:

    f = wx-+ x-z + w

    -xz-+ wy

    -

    Minimal product:

    f = (w+x+z)(w+x-+z-)(w-+x-+y-)

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    - 4.31 -

    4.11. (continued)

    (g)

    Minimal sum:

    f = x-z- + wy- + w-xy

    Minimal product:

    f = (w+y)(w-+x-+y-)(x+y

    -+z-)

    (h)

    Minimal sum:

    f = w-y + xy

    -+ y-z + xz

    Minimal products:

    f = (x+y+z)(w-+x+y

    -)(x-+y-+z)

    f = (x+y+z)(w-+x+y

    -)(w-+y-+z)

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    - 4.32 -

    4.11. (continued)

    (i)

    Minimal sum:

    f = w-y-+ y-z + wyz

    -+ w-x

    Minimal product:

    f = (w-+y+z)(w+x+y

    -)(w-+y-+z-)

    (j)

    Minimal sums:

    f = w-z + wz

    -+ w-xy-

    f = w-z + wz

    -+ xy

    -z-

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    - 4.33 -

    4.11. (continued)

    Minimal products:

    f = (w-+z-)(y

    -+z)(w+x+y)

    f = (w-+z-)(y

    -+z)(w+x+z)

    4.12. (a)

    Minimal sums:

    f = w-x + wx

    -y + wz

    f = w-x + wx-y + y-z

    Minimal products:

    f = (y+z)(w+x)(w-+x-+y-)

    f = (y+z)(w+x)(w-+x-+z)

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    4.12. (continued)

    (b)

    Minimal sums:

    f = wx-y- + w-y-z + wxy

    f = wx-y-+ w

    -y-z + xyz

    -

    Minimal products:

    f = (x+y-)(w+z)(w

    -+x-+y)(y

    -+z-)

    f = (x+y-)(w+z)(w

    -+x-+y)(w+y

    -)

    (c)

    Minimal sum:

    f = x-z-+ w-y-

    + wxz

    Minimal product:

    f = (x+z-)(w-+x-+z)(w+x

    -+y-)

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    4.12. (continued)

    (d)

    Minimal sums:

    f = w-x-z + w

    -xz-+ wxy

    -

    f = w-x-z + w

    -xz-+ xy

    -z-

    Minimal product:

    f = (x+z)(x-+z-)(w-+y-)

    (e)

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    4.12. (continued)

    Minimal sums:

    f = w-y-+ y-z + w

    -x-

    f = w-y-+ y-z + x

    -y

    Minimal product:

    f = (w-+z)(x

    -+y-)

    (f)

    Minimal sum:

    f = xz-+ w-y + x

    -y-z

    Minimal product:

    f = (x-+z-)(x+y+z)(w

    -+x+y

    -)

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    - 4.37 -

    4.12. (continued)

    (g)

    Minimal sum:

    f = wx + w-x-y + wy

    -z-+ xz

    -

    Minimal products:

    f = (w+y)(w+x-+z-)(w-+x+y

    -)(w-+x+z

    -)

    f = (w+y)(w+x-+z-)(w-+x+y

    -)(x+y+z

    -)

    (h)

    Minimal sum:

    f = w-y + wz

    -+ w-xz

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    4.12. (continued)

    Minimal products:

    f = (w-+z-)(w+y+z)(w+x+y)

    f = (w-+z-)(w+y+z)(x+y+z

    -)

    (i)

    Minimal sum:

    f = xy + xz + wyz + wy-z-

    Minimal products:

    f = (w+x)(w+y+z)(x+y+z-)(w-+y-+z)

    f = (w+x)(w+y+z)(x+y+z-)(x+y

    -+z)

    (j)

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    - 4.39 -

    4.12. (continued)

    Minimal sum:

    f = xy + wz-+ w-y-z

    Minimal product:

    f = (w+z)(x+y-)(w-+y+z-)

    4.13.

    To construct f2:

    If g=1 and f1=1, then f

    2=1.

    If g=0 and f1=0, then f

    2=-.

    If g=0 and f1=1, then f

    2=0.

    (Note: g=1 and f1=0 can not occur if the problem is

    solvable.)

    Using the above rules, the map for f2is:

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    4.13. (continued)

    Minimal sum:

    f2= xy

    -+w-z

    Minimal products:

    f2 = (x+z)(y-+z)(w-+x) (Shown above)

    Other possible minimal products:

    f2= (x+z)(y

    -+z)(w

    -+y-)

    f2= (x+z)(x

    -+y-)(w-+x)

    f2= (x+z)(x

    -+y-)(w-+y-)

    4.14. (a)

    Minimal sums:

    f = v-y-z + vwy + vxy

    -+ v-wx-z

    f = v-y-z + vwy + vxy

    -+ wx

    -yz

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    4.14. (continued)

    Minimal product:

    f = (w+y-)(v+z)(v

    -+x+y)(v+x

    -+y-)

    (b)

    Minimal sum:

    f = yz + v-wy-+ vw

    -y-z-+ vwxy

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    - 4.42 -

    4.14. (continued)

    Minimal products (shown above):

    f = (v-+w-+y)(v+y

    -+z)(w+y

    -+z)(x+y

    -+z)(v+w+y)(v

    -+y+z

    -)

    f = (v-+w-+y)(v+y

    -+z)(w+y

    -+z)(x+y

    -+z)(v+w+y)(w+y+z

    -)

    Another minimal product (not shown):

    f = (v-+w-+y)(v+y

    -+z)(w+y

    -+z)(x+y

    -+z)(w+y+z

    -)(v+w+z)

    (c)

    Minimal sums (shown above):

    f = vwz-+ w

    -x-z + vy

    -z-+ v-w-xy-+ v

    -wxy + v

    -x-yz

    f = vwz-+ w-x-z + vy

    -z-+ v-w-xy-+ v

    -wxy + v

    -wyz

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    4.14. (continued)

    Another minimal sum (not shown):

    f = vwz-+ w

    -x-z + vy

    -z-+ v-w-xy-

    + v-wyz + wxyz

    -

    Minimal product:

    f = (v+x+z)(v+w-+y)(v

    -+w-+z-)(w+x

    -+y-)(v-+x-+z-)(w+y

    -+z)

    (d)

    Minimal sum:

    f = w-z + y

    -z + wx

    -y + vwy

    -

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    4.14. (continued)

    Minimal product:

    f = (w+z)(w-+x-+y-)(v+y+z)

    4.15.

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    4.15. (continued)

    Minimal sums:

    f = v-wz-+ uvw

    -+ v-w-x + uvz

    -

    f = v-wz-+ uvw

    -+ v-w-x + uwz

    -

    Minimal product:

    f = (u+v-)(w-+z-)(v+w+x)

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    4.16.

    x y z f

    0 0 0 0

    0 0 1 0

    0 1 0 0

    0 1 1 1

    1 0 0 0

    1 0 1 1

    1 1 0 1

    1 1 1 1

    Minimal sum (cost=9): f = xy + xz + yz

    Minimal product (cost=9): f = (x+y)(x+z)(y+z)

    Realization using the minimal sum:

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    4.17.

    Minimal sum (cost=20):

    p = wz + xy-z + xyz- + x-yz + w-x-y-z-

    Minimal product (cost=20):

    p = (w-+z)(x

    -+y+z)(x

    -+y-+z-)(x+y

    -+z)(w+x+y+z

    -)

    Comparing Tables 3.10 and 3.12, it is seen that if the

    don't-cares for wxyz=1010, 1100, and 1111 are assigned

    values of logic-1, the two tables become identical.

    Since Table 3.10 is describable by the expression

    p=(w-rx)r(yrz), this same expression can be used for

    Table 3.12.

    4.18. Truth table:

    xi

    yi

    ci

    ci+1

    si

    0 0 0 0 0

    0 0 1 0 1

    0 1 0 0 1

    0 1 1 1 0

    1 0 0 0 1

    1 0 1 1 0

    1 1 0 1 0

    1 1 1 1 1

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    4.18. (continued)

    For the ci+1

    output:

    Minimal sum (cost=9):

    ci+1

    = xiyi+ x

    ici+ y

    ici

    Minimal product (cost=9)

    ci+1

    = (xi+yi)(x

    i+ci)(y

    i+ci)

    For the sioutput:

    Minimal sum (cost=16):

    si= x-iy-ici

    + x-iyic-i+ x

    iy-ic-i+ x

    iyici

    Minimal product (cost=16)

    si= (x

    i+yi+c

    i)(x

    i+y-i+c-i)(x-i+y

    i+c-i)(x-i+y-i+ c

    i)

    However,

    si= x-

    iy-ici+ x-

    iyic-i+ x

    iy-ic-i

    + xiyici

    = x-i(y-ici+y

    ic-i) + x

    i(y-ic-i+ y

    ici)

    = x-i(yirc

    i) + x

    i(yirc

    i)

    _______

    = xir (y

    irc

    i)

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    4.18. (continued)

    Realization:

    4.19. Truth table:

    x

    i

    y

    i

    b

    i

    b

    i+1

    d

    i

    0 0 0 0 0

    0 0 1 1 1

    0 1 0 1 1

    0 1 1 1 0

    1 0 0 0 1

    1 0 1 0 0

    1 1 0 0 0

    1 1 1 1 1

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    4.19. (continued)

    For the bi+1

    output:

    Minimal sum (cost=9):

    bi+1

    = x-iyi+ x-ibi+ y

    ibi

    Minimal product (cost=9):

    bi+1

    = (x-i+yi)(x-

    i+bi)(y

    i+bi)

    For the dioutput:

    Minimal sum (cost=16):

    di= x-iy-ibi

    + x-iyib-i+ x

    iy-ib-i+ x

    iyibi

    Minimal product (cost=16):

    di= (x

    i+yi+b

    i)(x

    i+y-i+b-i)(x-i+y

    i+b-i)(x-i+y-i+bi)

    However,

    di= x-

    iy-ibi+ x-

    iyib-i+ x

    iy-ib-i

    + xiyibi

    = x-(y-ibi+yib-i) + x

    i(y-ib-i+yibi)

    = x-i(yirb

    i) + x

    i(yirb

    i)

    _______

    = xir (y

    irb

    i)

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    4.19. (continued)

    Realization:

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    4.20.

    8 4 2 1

    w x y z f

    0 0 0 0 0

    0 0 0 1 0

    0 0 1 0 0

    0 0 1 1 0

    0 1 0 0 0

    0 1 0 1 0

    0 1 1 0 0

    0 1 1 1 0

    1 0 0 0 0

    1 0 0 1 0

    1 0 1 0 1

    1 0 1 1 1

    1 1 0 0 1

    1 1 0 1 1

    1 1 1 0 1

    1 1 1 1 1

    Minimal sum (cost=6):

    f = wx + wy

    Minimal product (cost=4):

    f = w(x+y)

    Realization:

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    4.21. Let:

    F=1 when the pressure in the fuel tank is equal to or above

    a required minimum.

    F=0 when the pressure in the fuel tank is below a required

    minimum.

    X=1 when the oxidizer tank pressure is equal to or above a

    required minimum.

    X=0 when the oxidizer tank pressure is below a required

    minimum.

    T=1 when there are 10 min. or less to lift off.

    T=0 when there are more than 10 min. to lift off.

    P=1 when the panel light is on.

    P=0 when the panel light is off.

    From the problem statement we can write the equation for

    the panel light to be on:

    P = FXT + F-XT-+ X-T-

    Minimal sum (cost=10):

    P = X-T-+ F-T-+ FXT

    Minimal product (cost=10):

    P = (F+T-)(X+T-)(F-+X-+T)

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    4.21. (continued)

    Realization using the minimal sum:

    4.22. Let w, x, y, and z denote the bits of the 2421 code groups

    and A, B, C, and D denote the bits of the 8421 code groups

    where w and A are the most significant bits of their

    respective code groups.

    w x y z A B C D

    0 0 0 0 0 0 0 0

    0 0 0 1 0 0 0 1

    0 0 1 0 0 0 1 0

    0 0 1 1 0 0 1 1

    0 1 0 0 0 1 0 0

    0 1 0 1 - - - -

    0 1 1 0 - - - -

    0 1 1 1 - - - -

    1 0 0 0 - - - -

    1 0 0 1 - - - -

    1 0 1 0 - - - -

    1 0 1 1 0 1 0 1

    1 1 0 0 0 1 1 0

    1 1 0 1 0 1 1 1

    1 1 1 0 1 0 0 0

    1 1 1 1 1 0 0 1

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    4.22. (continued)

    A = xy B = xy-+ wx

    -(cost=6)

    B = (w+x)(x-+y-) (cost=6)

    C = wy-+ w-y (cost=6) D = z

    C = (w+y)(w-+y-) (cost=6)

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    4.23.

    7 5 3 6-

    w x y z f

    0 0 0 0 1

    0 0 0 1 -

    0 0 1 0 1

    0 0 1 1 -

    0 1 0 0 0

    0 1 0 1 -

    0 1 1 0 0

    0 1 1 1 1

    1 0 0 0 0

    1 0 0 1 1

    1 0 1 0 -

    1 0 1 1 0

    1 1 0 0 -

    1 1 0 1 0

    1 1 1 0 -

    1 1 1 1 0

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    4.23. (continued)

    Minimal sum (cost=10):

    f = w-x-+ w-z + x

    -y-z

    Minimal products (cost=12):

    f = (x-+z)(w-+z)(w-+y-)(w-+x-)

    f = (x-+z)(w

    -+z)(w

    -+y-)(x-+y)

    Realization:

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    4.24.

    Inputs Outputs

    8 4 2 1

    w x y z a b c d e f g

    0 0 0 0 1 1 1 1 1 1 0

    0 0 0 1 0 1 1 0 0 0 0

    0 0 1 0 1 1 0 1 1 0 1

    0 0 1 1 1 1 1 1 0 0 1

    0 1 0 0 0 1 1 0 0 1 1

    0 1 0 1 1 0 1 1 0 1 1

    0 1 1 0 1 0 1 1 1 1 1

    0 1 1 1 1 1 1 0 0 0 0

    1 0 0 0 1 1 1 1 1 1 1

    1 0 0 1 1 1 1 1 0 1 1

    1 0 1 0 - - - - - - -

    1 0 1 1 - - - - - - -

    1 1 0 0 - - - - - - -

    1 1 0 1 - - - - - - -

    1 1 1 0 - - - - - - -

    1 1 1 1 - - - - - - -

    a = w + y + xz + x-z-

    b = x-+ y-z-+ yz

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    4.24. (continued)

    c = x + y-+ z d = w + yz

    -+ x-y + x

    -z-+ xy

    -z

    e = x-z-+ yz

    -f = w + y

    -z-+ xy

    -+ xz

    -

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    4.24. (continued)

    g = w + xy-+ x

    -y + yz

    -or g = w + xy

    -+ x-y + xz

    -

    4.25. (a)

    wxyz wxyz wxyz

    0 0000 T 0,2 00-0 T 0,2,8,10 -0-0 A

    2 0010 T 0,4 0-00 T 0,4,8,12 --00 B

    4 0100 T 0,8 -000 T 8,10,12,14 1--0 C

    8 1000 T 2,3 001- D

    3 0011 T 2,10 -010 T

    10 1010 T 4,12 -100 T

    12 1100 T 8,10 10-0 T

    13 1101 T 8,12 1-00 T

    14 1110 T 10,14 1-10 T

    12,13 110- E

    12,14 11-0 T

    The prime implicants are:

    A: x-z-

    B: y-z-

    C: wz-

    D: w-x-y

    E: wxy-

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    4.25. (continued)

    (b)

    vwxyz vwxyz vwxyz

    4 00100 T 4,5 0010- T 4,5,6,7 001-- A

    5 00101 T 4,6 001-0 T 10,14,26,30 -1-10 B

    6 00110 T 5,7 001-1 T

    9 01001 E 6,7 0011- T

    10 01010 T 6,14 0-110 C

    7 00111 T 10,14 01-10 T

    14 01110 T 10,26 -1010 T

    19 10011 F 14,30 -1110 T

    26 11010 T 26,30 11-10 T

    30 11110 T 30,31 1111- D

    31 11111 T

    The prime implicants are:

    A: v-w-x

    B: wyz-

    C: v-xyz-

    D: vwxy

    E: v-wx-y-z

    F: vw-x-yz

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    4.25. (continued)

    (c)

    wxyz wxyz wxyz

    4 0100 T 4,12 -100 C 9,11,13,15 1--1 A

    9 1001 T 9,11 10-1 T 12,13,14,15 11-- B

    12 1100 T 9,13 1-01 T

    7 0111 T 12,13 110- T

    11 1011 T 12,14 11-0 T

    13 1101 T 7,15 -111 D

    14 1110 T 11,15 1-11 T

    15 1111 T 13,15 11-1 T

    14,15 111- T

    The prime implicants are:

    A: wz

    B: wx

    C: xy-z-

    D: xyz

    (d)

    wxyz wxyz wxyz

    0 0000 T 0,1 000- T 0,1,2,3 00-- A

    1 0001 T 0,2 00-0 T 1,3,5,7 0--1 B

    2 0010 T 1,3 00-1 T 2,3,6,7 0-1- C

    3 0011 T 1,5 0-01 T

    5 0101 T 1,9 -001 D

    6 0110 T 2,3 001- T

    9 1001 T 2,6 0-10 T

    10 1010 T 2,10 -010 E

    12 1100 F 3,7 0-11 T

    7 0111 T 5,7 01-1 T

    6,7 011- T

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    4.25. (continued)

    The prime implicants are:

    A: w-x-

    B: w-z

    C: w-y

    D: x-y-z

    E: x-yz-

    F: wxy-z-

    4.26. (a)

    vwxyz vwxyz vwxyz

    1 00001 T 1,3 000-1 T 1,3,17,19 -00-1 A

    3 00011 T 1,17 -0001 T 6,14,22,30 --110 B

    6 00110 T 3,11 0-011 D 10,11,14,15 01-1- C

    10 01010 T 3,19 -0011 T

    12 01100 T 6,14 0-110 T

    17 10001 T 6,22 -0110 T

    20 10100 T 10,11 0101- T

    24 11000 G 10,14 01-10 T

    11 01011 T 12,14 011-0 E

    14 01110 T 17,19 100-1 T

    19 10011 T 20,22 101-0 F

    22 10110 T 11,15 01-11 T

    15 01111 T 14,15 0111- T

    29 11101 H 14,30 -1110 T

    30 11110 T 22,30 1-110 T

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    4.26. (continued)

    The prime implicates are:

    A: w+x+z-

    B: x-+y-+z

    C: v+w-+y-

    D: v+x+y-+z-

    E: v+w-+x-+z

    F: v-+w+x

    -+z

    G: v-+w-+x+y+z

    H: v-+w-+x-+y+z

    -

    (b)

    wxyz wxyz wxyz

    0 0000 T 0,2 00-0 T 0,2,8,10 -0-0 A

    2 0010 T 0,4 0-00 T 0,4,8,12 --00 B

    4 0100 T 0,8 -000 T 4,5,12,13 -10- C

    8 1000 T 2,3 001- D

    3 0011 T 2,10 -010 T

    5 0101 T 4,5 010- T

    10 1010 T 4,12 -100 T

    12 1100 T 8,10 10-0 T

    13 1101 T 8,12 1-00 T

    5,13 -101 T

    12,13 110- T

    The prime implicates are:

    A: x+z

    B: y+z

    C: x-+y

    D: w+x+y-

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    4.27. (a)

    wxyz wxyz

    4 0100 T 4,5 010- A

    5 0101 T 4,12 -100 B

    12 1100 T 5,7 01-1 C

    7 0111 T 12,14 11-0 D

    14 1110 T 7,15 -111 E

    15 1111 T 14,15 111- F

    m4

    m5

    m7

    m12

    m14

    m15

    A: w-xy-

    B: xy-z-

    C: w-xz

    D: wxz-

    E: xyz

    F: wxy

    p = (A+B)(A+C)(C+E)(B+D)(D+F)(E+F)

    = (B+AD)(C+AE)(F+DE)

    = (BC+ABE+ACD+ADE)(F+DE)

    = BCF + BCDE + ABEF + ABDE + ACDF + ACDE + ADEF + ADE

    = BCF + ADE + BCDE + ABEF + ACDF

    There are five irredundant disjunctive normal formulas:

    f1= B + C + F = xy

    -z-+ w-xz + wxy

    f2= A + D + E = w

    -xy-+ wxz

    -+ xyz

    f3 = B + C + D + E = xy-z- + w-xz + wxz- + xyz

    f4= A + B + E + F = w

    -xy-+ xy

    -z-

    + xyz + wxy

    f5= A + C + D + F = w

    -xy-+ w-xz + wxz

    -+ wxy

    The costs of f1and f

    2are 12; while the costs of f

    3,

    f4, and f

    5are 16. Therefore, f

    1and f

    2are minimal

    sums.

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    4.27. (continued)

    (b)

    wxyz wxyz wxyz

    0 0000 T 0,4 0-00 T 0,4,8,12 --00 A

    4 0100 T 0,8 -000 T 4,5,12,13 -10- B

    8 1000 T 4,5 010- T 8,9,10,11 10-- C

    3 0011 T 4,12 -100 T 8,9,12,13 1-0- D

    5 0101 T 8,9 100- T

    9 1001 T 8,10 10-0 T

    10 1010 T 8,12 1-00 T

    12 1100 T 3,7 0-11 E

    7 0111 T 3,11 -011 F

    11 1011 T 5,7 01-1 G

    13 1101 T 5,13 -101 T

    9,11 10-1 T

    9,13 1-01 T

    10,11 101- T

    12,13 110- T

    m4

    m5

    m8

    m9

    m12

    m13

    A: y-z-

    B: xy-

    C: wx-

    D: wy-

    G: w-xz

    (Note: Prime implicants E and F do not appear in the

    prime-implicant table since they do not cover any of

    the minterms having functional values of 1.)

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    4.27. (continued)

    p = (A+B)(B+G)(A+C+D)(C+D)(A+B+D)(B+D)

    = (A+B)(B+G)(C+D)(B+D)

    = (B+AG)(D+BC)

    = BD + BC + ADG + ABCG

    = BD + BC + ADG

    There are three irredundant disjunctive normal

    formulas:

    f1= B + D = xy

    -+ wy

    -

    f2= B + C = xy

    -+ wx

    -

    f3= A + D + G = y

    -z-+ wy

    -+ w-xz

    The costs of f1

    and f2are 6 and the cost of f

    3is 10.

    Therefore, f1and f

    2are minimal sums.

    4.28. (a)

    wxyz wxyz wxyz

    4 0100 T 4,5 010- B 9,11,13,15 1--1 A

    8 1000 T 8,9 100- C

    3 0011 T 3,11 -011 D

    5 0101 T 5,13 -101 E

    9 1001 T 9,11 10-1 T

    11 1011 T 9,13 1-01 T

    13 1101 T 11,15 1-11 T

    14 1110 T 13,15 11-1 T

    15 1111 T 14,15 111- F

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    4.28. (continued)

    M3

    M4

    M5

    M8

    M9

    M11

    M13

    M14

    M15

    A: w-+z-

    B: w+x-+y

    C: w-+x+y

    D: x+y-+z-

    E: x-+y+z

    -

    F: w-+x-+y-

    p = DB(B+E)C(A+C)(A+D)(A+E)F(A+F)

    = BCDF(A+E)= ABCDF + BCDEF

    There are two irredendant conjunctive normal formulas:

    f1= ABCDF = (w

    -+z-)(w+x

    -+y)(w

    -+x+y)(x+y

    -+z-)(w-+x-+y-)

    f2= BCDEF = (w+x

    -+y)(w

    -+x+y)(x+y

    -+z-)(x-+y+z

    -)(w-+x-+y-)

    The cost of f1is 19 and the cost of f

    2is 20.

    Therefore, f1 is the minimal product.

    (b)

    wxyz wxyz wxyz

    0 0000 T 0,8 -000 B 5,7,13,15 -1-1 A

    8 1000 T 8,9 100- C

    5 0101 T 5,7 01-1 T

    6 0110T

    5,13 -101T

    9 1001 T 6,7 011- D

    7 0111 T 9,13 1-01 E

    13 1101 T 7,15 -111 T

    15 1111 T 13,15 11-1 T

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    4.28. (continued)

    M0

    M6

    M7

    M8

    M9

    M13

    A: x-+z-

    B: x+y+z

    C: w-+x+y

    D: w+x-+y-

    E: w-+y+z

    -

    p = BD(A+D)(B+C)(C+E)(A+E)

    = BD(C+E)(A+E)

    = BD(E+AC)

    = BDE + ABCD

    There are two irredundant conjunctive normal formulas:

    f1= BDE = (x+y+z)(w+x

    -+y-)(w-+y+z

    -)

    f2= ABCD = (x

    -+z-)(x+y+z)(w

    -+x+y)(w+x

    -+y-)

    The cost of f1is 12 and the cost of f

    2is 15.

    Therefore, f1is the minimal product.

    4.29. (a) Referring to Table P4.29a, c2dominates c

    1, c

    6

    dominates c1, c6 dominates c2, c3 dominates c7, and c5dominates c

    7. Deleting the dominating columns c

    2, c

    3,

    c5, and c

    6, the table reduces to

    c1

    c4

    c7

    cost

    r1

    3

    r2

    4

    r4

    4

    r5 4

    r6

    6

    r7

    6

    (Note: r3no longer appears since it has no crosses in

    the remaining columns.)

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    4.29. (continued)

    r1equals r

    5, r

    2equals r

    7, and r

    4equals r

    6. Deleting

    those rows with the higher costs, i.e., r5, r

    6, and r

    7,

    the table becomes

    c1

    c4

    c7

    cost

    **r1

    3

    **r2

    4

    **r4

    4

    Since only single crosses exist in each column, the

    minimal cover consists of rows r1, r

    2, and r

    4.

    (b) Referring to Table P4.29b, r3is an essential prime

    implicant since c11

    has a single cross. Therefore, r3

    must be selected and r3and c

    11can be deleted from the

    table. Also, c1dominates c

    8, c

    2dominates c

    5, c

    9

    dominates c3, and c

    10dominates c

    6. Thus, columns c

    1,

    c2, c

    9, and c

    10are deleted. The table now reduces to

    c3

    c4

    c5

    c6

    c7

    c8

    cost

    r1

    3

    r2

    3

    r4

    4

    r5

    4

    r6

    5

    r7 6

    r8

    7

    r9

    7

    Minimal cover: {r3,...}

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    4.29. (continued)

    r1now dominates r

    5, r

    1dominates r

    6, r

    8dominates r

    2,

    r7dominates r

    4, and r

    5dominates r

    6. Rows r

    5and r

    6

    are deleted since they have a higher cost than their

    dominating rows. However, r2 and r4 cannot be deleted

    since they have a lower cost than their dominating

    rows. The resulting table is

    c3

    c4

    c5

    c6

    c7

    c8

    cost

    **r1

    3

    r2

    3

    r4

    4

    r7

    6

    r8

    7

    r9

    7

    Minimal cover: {r3,...}

    Since column c4 has a single cross, row r1 is selected

    to appear in the minimal cover. After deleting row r1

    and columns c4, c

    5, and c

    7, the table reduces to

    c3

    c6

    c8

    cost

    r2

    3

    r4

    4

    r7 6

    r8

    7

    r9

    7

    Minimal cover: {r1,r3,...}

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    4.29. (continued)

    r4equals r

    7and the cost of r

    4is less than the cost

    of r7. Therefore, delete r

    7. Also, r

    8dominates r

    9.

    r9is deleted since it has equal cost. The table

    becomes

    c3

    c6

    c8

    cost

    r2

    3

    **r4

    4

    **r8

    7

    Minimal cover: {r1,r3,...}

    Finally, since columns c3and c

    8have single crosses,

    rows r4and r

    8must appear in the minimal cover. This

    completes the covering of the prime-implicant table.

    The minimal cover consists of rows r1, r

    3, r

    4, and r

    8.

    (c) Referring to Table P4.29c, c

    5

    dominates c

    1

    , c

    2

    equals

    c6, and c

    3dominates c

    7. Deleting c

    3, c

    5, and c

    6, the

    table reduces to

    c1

    c2

    c4

    c7

    cost

    r1

    3

    r2

    4

    r3

    4

    r4

    5

    r5

    5

    r6

    6

    r7

    7

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    4.29. (continued)

    r6dominates r

    1, but cost prevents deleting r

    1.

    However, since r2dominates r

    5, r

    2dominates r

    7, r

    3

    dominates r7, and r

    4dominates r

    5, and since the

    dominated rows have a greater or equal cost than the

    dominating rows, delete r5and r

    7. The table now

    becomes

    c1

    c2

    c4

    c7

    cost

    r1

    3

    r2

    4

    r3

    4

    r4

    5

    r6

    6

    The resulting table cannot be reduced any further.

    Petrick's method should be applied.

    p = (r1+r6)(r

    3+r4+r6)(r

    2+r3)(r

    2+ r

    4)

    = (r6+r1r3+r1r4)(r2+r3r4)= r

    2r6+ r

    3r4r6+ r

    1r2r3+ r

    1r3r4+ r

    1r2r4+ r

    1r3r4

    = r2r6+ r

    3r4r6+ r

    1r2r3+ r

    1r3r4+ r

    1r2r4

    Irredundant

    cover

    cost

    r2, r

    610

    r3, r

    4, r

    615

    r1, r

    2, r

    311

    r1, r

    3, r

    412

    r1, r

    2, r

    412

    The minimal cost cover consists of rows r2and r

    6.

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    4.30.

    wxyz wxyz

    2 0010 T 2,3 001- A

    4 0100 T 2,10 -010 B

    3 0011 T 4,5 010- C

    5 0101 T 4,12 -100 D

    10 1010 T 3,7 0-11 E

    12 1100 T 5,7 01-1 F

    7 0111 T 10,14 1-10 G

    14 1110 T 12,14 11-0 H

    15 1111 T 7,15 -111 I

    14,15 111- J

    m3

    m4

    m5

    m7

    m10

    m12

    m14

    m15

    cost

    A 4

    B 4

    C 4

    D 4

    E 4

    F 4

    G 4

    H 4

    I 4

    J 4

    Row E dominates row A and row G dominates row B. Since

    all rows have equal cost, delete rows A and B. The

    reduced table is

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    4.30. (continued)

    m3

    m4

    m5

    m7

    m10

    m12

    m14

    m15

    cost

    C 4

    D 4

    **E 4

    F 4

    **G 4

    H 4

    I 4

    J 4

    Select prime implicants E and G for a minimal sum since

    columns m3and m

    10each have a single cross. Delete

    rows E and G as well as the columns having crosses in

    these rows. The reduced table becomes

    m4

    m5

    m12

    m15

    cost

    C 4

    D 4

    F 4

    H 4

    I 4

    J 4

    Minimal sum: f = E + G +...

    Row C dominates row F, row D dominates row H, and rows

    I and J are equal. Since all rows have the same cost,

    delete rows F, H, and J. The resulting table is

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    4.30. (continued)

    m4

    m5

    m12

    m15

    cost

    **C 4

    **D 4

    **I 4

    Minimal sum: f = E + G + ...

    Since columns m5, m

    12, and m

    15each have a single

    cross, rows C, D, and I are selected for a minimal sum.

    Furthermore, by selecting these rows, all the columns

    of the above table are covered. The minimal sum is

    f = C + D + E + G + I

    = w-xy-+ xy

    -z-+ w-yz + wyz

    -+ xyz

    (Note: If row I was deleted since it was equal to row

    J, then the minimal cover would consist of rows C,

    D, E, G, and J. Applying Petrick's method to the

    original prime-implicant table would result in 16

    minimal sums of which only 2 are readily found when

    using table reduction procedures.)

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    4.31.

    1 T 1,3 (2) C 8,9,12,13 (1,4) A

    8 T 1,9 (8) D 8,10,12,14 (2,4) B

    3 T 8,9 (1) T

    6 T 8,10 (2) T

    9 T 8,12 (4) T

    10 T 3,7 (4) E

    12 T 6,7 (1) F

    7 T 6,14 (8) G

    13 T 9,13 (4) T

    14 T 10,14 (4) T

    12,13 (1) T

    12,14 (2) T

    Prime implicants:

    wxyz

    A: 1-0- 6 wy-

    B: 1--0 6 wz-

    C: 00-1 6 w-x-z

    D: -001 6 x-y-z

    E: 0-11 6 w-yz

    F: 011- 6 w-xy

    G: -110 6 xyz-

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    4.31. (continued)

    m1

    m3

    m6

    m8

    m9

    m10

    m12

    m14

    cost

    A 3

    *B 3

    C 4

    D 4

    E 4

    F 4

    G 4

    B is an essential prime implicant. Selecting row B and

    deleting the columns having crosses in row B, the table

    reduces to

    m1

    m3

    m6

    m9

    cost

    A 3

    C 4

    D 4

    E 4

    F 4

    G 4

    Minimal sum: f = B + ...

    Even though row D dominates row A, row A cannot be deleted

    because of cost. Row C dominates row E and rows F and G

    are equal. Since these rows have the same cost, delete

    rows E and G. The table becomes

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    4.31. (continued)

    m1

    m3

    m6

    m9

    cost

    A 3

    **C 4

    D 4

    **F 4

    Minimal sum: f = B + ...

    Since columns m3and m

    6have single crosses, rows C and F

    must be selected. After deleting rows C and F and the

    columns having crosses in these rows, the reduced table is

    m9

    cost

    A 3

    D 4

    Minimal sum: f = B + C + F + ...

    Row D can be eliminated since it is equal to row A and has

    a higher cost. This results in the table

    m9

    cost

    **A 3

    Minimal sum: f = B + C + F + ...

    Selecting row A, the minimal sum is

    f = A + B + C + F = wy-+ wz

    -+ w-x-z + w

    -xy

    (Note: At an earlier point, row F could have been deleted

    since it was equal to row G. In this case, a minimal

    sum is

    f = A + B + C + G = wy-+ wz

    -+ w

    -x-z + xyz

    -)

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    4.32.

    xyz xyz

    0 000 f1_

    f3

    F 0,2 (2) 0-0_ _

    f3A

    2 010_

    f2f3T 2,3 (1) 01-

    _ _f3B

    3 011 f1_

    f3

    G 2,6 (4) -10_

    f2f3C

    5 101 f1f2_

    H 3,7 (4) -11 f1_ _

    D

    6 110_

    f2f3T 5,7 (2) 1-1 f

    1_ _

    E

    7 111 f1_ _

    T

    f1

    f2

    f3

    m0 m3 m5 m7 m2 m5 m6 m0 m2 m3 m6

    A: x-z-

    B: x-y

    C: yz-

    D: yz

    E: xz

    F: x-y-z-

    G: x

    -

    yz

    H: xy-z

    p = F1(D1+G1)(E

    1+H1)(D

    1+E1)C2H2C2(A3+F

    3)(A

    3+B3+C3)(B

    3+G3)C3

    = F1C2H2C3(D1+G1)(E

    1+H1)(D

    1+E1)(A

    3+F3)(B

    3+G3)

    = F1C2H2C3(D1+G1)(E

    1+D

    1H1)(A

    3+F3)(B

    3+G3)

    = F1C2H2C3(D1E1+D1H1+E1G1+D1G1H1)(A

    3B3+A3G3+B3F3+F3G3)

    = F1C2H2C3(D1E1A3B3+D1E1A3G3+D1E1B3F3+D1E1F3G3+D1H1A3B3

    +D1H1A3G3+D1H1B3F3+D1H1F3G3+E1G1A3B3+E1G1A3G3

    +E1G1B3F3+E1G1F3G3)

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    4.32. (continued)

    = A3B3C2C3D1E1F1H2+ A

    3C2C3D1E1F1G3H2+ B

    3C2C3D1E1F1F3H2

    + C2C3D1E1F1F3G3H2+ A

    3B3C2C3D1F1H1H2

    + A3C2C3D1F1G3H1H2+ B

    3C2C3D1F1F3H1H2

    + C2C3D1F1F3G3H1H2 + A3B3C2C3E1F1G1H2

    + A3C2C3E1F1G1G3H2+ B

    3C2C3E1F1F3G1H2

    + C2C3E1F1F3G1G3H2

    Product terms Distinct terms Input terminals (E"i+G$

    j)

    A3B3C2C3D1E1F1H2

    7 8 + 16 = 24

    A3C2C3D1E1F1G3H2

    7 8 + 17 = 25

    B3C2C3D1E1F1F3H2 6 8 + 14 = 22

    C2C3D1E1F1F3G3H2

    6 8 + 15 = 23

    A3B3C2C3D1F1H1H2

    6 8 + 14 = 22

    A3C2C3D1F1G3H1H2

    6 8 + 15 = 23

    B3C2C3D1F1F3H1H2

    5 * 8 + 12 = 20 *

    C2C3D1F1F3G3H1H2

    5 * 8 + 13 = 21

    A3B3C2C3E1F1G1H2

    7 8 + 17 = 25

    A3C2C3E1F1G1G3H2 6 8 + 15 = 23

    B3C2C3E1F1F3G1H2

    6 8 + 15 = 23

    C2C3E1F1F3G1G3H2

    5 * 8 + 13 = 21

    There are three multiple-output minimal sums when the cost

    is based on number of distinct terms:

    f1= yz + x

    -y-z-+ xy

    -z f

    1= yz + x

    -y-z-+ xy

    -z

    f2= yz

    -+ xy

    -z f

    2= yz

    -+ xy

    -z

    f3= x-y + yz- + x-y-z- f

    3= yz- + x-y-z- + x-yz

    f1= xz + x

    -y-z-+ x-yz

    f2= yz

    -+ xy

    -z

    f3= yz

    -+ x-y-z-

    + x-yz

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    4.32. (continued)

    There is only one multiple-output minimal sum when the cost

    is based on number of input terminals in the realization:

    f1= yz + x

    -y-z-+ xy

    -z

    f2 = yz- + xy-z

    f3= x-y + yz

    -+ x-y-z-

    4.33. (a)

    xyz xyz xyz

    0 000 f1f2_

    T 0,2 (2) 0-0 f1f2_

    B 0,2,4,6 (2,4) --0 f1_ _

    A

    2 010 f1f2_

    T 0,4 (4) -00 f1_ _

    T

    4 100 f1_

    f3T 2,3 (1) 01- f1_ _

    C

    3 011 f1_

    f3F 2,6 (4) -10 f

    1_ _

    T

    5 101_

    f2f3G 4,5 (1) 10-

    _ _f3D

    6 110 f1_

    f3T 4,6 (2) 1-0 f

    1_

    f3E

    f1

    f2

    f3

    m0

    m2

    m3

    m4

    m6

    m0

    m2

    m5

    m3

    m4

    m5

    m6

    cost

    A: z- 1

    *2 B: x-z-

    3,4

    C: x-y 3

    D: xy-

    3

    *3 E: xz-

    3,4

    *3 F: x-yz 4,5

    *2 G: xy-z 4,5

    f1= ... f

    2= x-z-+ xy

    -z f

    3= xz

    -+ x-yz + ...

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    4.33. (continued)

    Reducing the table:

    f

    1

    f

    3m0

    m2

    m3

    m4

    m6

    m5

    cost

    A: z-

    1

    B: x-z-

    1

    C: x-y 3

    D: xy-

    3

    E: xz-

    1

    F: x-yz 1

    G: xy-z 1

    f1= ... f

    2= x-z-+ xy

    -z f

    3= xz

    -+ x-yz + ...

    After deleting dominated and equal rows B, E, and D,

    the table becomes

    f1 f3

    m0

    m2

    m3

    m4

    m6

    m5

    cost

    *1 A: z-

    1

    C: x-y 3

    F: x-yz 1

    *3 G: xy-z 1

    f1 = z-+ ... f2 = x

    -z-+ xy

    -z f3 = xz

    -+ x-yz + xy

    -z

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    4.33. (continued)

    Reducing the table:

    f

    1m3

    cost

    C: x-y 3

    F: x-yz 1

    f1= z-+ ... f

    2= x-z-+ xy

    -z f

    3= xz

    -+ x-yz + xy

    -z

    To cover the remain column, select F. The multiple-

    output minimal sum is

    f1= z-+ x-yz

    f2= x-z-+ xy

    -z

    f3= xz

    -+ x-yz + xy

    -z

    (b)

    xyz xyz xyz

    0 000_ _

    f

    3

    T 0,1 (1) 00-_ _

    f

    3

    C 1,3,5,7 (2,4) --1_

    f

    2

    _A

    1 001 f1f2f3J 0,4 (4) -00

    _ _f3D 4,5,6,7 (1,2) 1--

    _f2_

    B

    2 010 f1_ _

    T 1,3 (2) 0-1_

    f2_

    T

    4 100_

    f2f3T 1,5 (4) -01 f

    1f2_

    E

    3 011_

    f2_

    T 2,6 (4) -10 f1_ _

    F

    5 101 f1f2_

    T 4,5 (1) 10-_

    f2_

    T

    6 110 f1f2f3K 4,6 (2) 1-0

    _f2f3G

    7 111 f

    1

    f

    2

    _T 3,7 (4) -11

    _f

    2

    _T

    5,7 (2) 1-1 f1f2_

    H

    6,7 (1) 11- f1f2_

    I

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    4.33. (continued)

    f1

    f2

    f3

    m1

    m2

    m5

    m3

    m5

    m6

    m7

    m1

    m4

    m6

    cost

    *2 A: z 1

    B: x 1

    C: x-y-

    3

    D: y-z-

    3

    E: y-z 3,4

    *1 F: yz-

    3

    G: xz-

    3,4

    H: xz 3,4

    I: xy 3

    J: x-y-z 4,5

    K: xyz-

    4,5

    f1= yz

    -+ ... f

    2= z + ... f

    3= ...

    Reducing the table:

    f

    1

    f

    2

    f

    3m1

    m5

    m6

    m1

    m4

    m6

    cost

    B: x 1

    C: x-y-

    3

    D: y-z-

    3

    E: y-z 3

    G: xz-

    3,4

    H: xz 3

    I: xy 3

    J: x-y-z 4,5

    K: xyz-

    4,5

    f1= yz

    -+ ... f

    2= z + ... f

    3= ...

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    4.33. (continued)

    After deleting equal row I and dominated rows D, H, and

    K, the table becomes

    f1

    f2

    f3

    m1

    m5

    m6

    m1

    m4

    m6

    cost

    B: x 1

    C: x-y-

    3

    *1 E: y-z 3

    *3 G: xz-

    3,4

    J: x-y-z 4,5

    f1= yz

    -+ y

    -z f

    2= z + ... f

    3= xz

    -+ ...

    Reducing the table:

    f2

    f3

    m6

    m1

    cost

    B: x 1

    C: x

    -

    y

    -

    3

    G: xz-

    1

    J: x-y-z 4,5

    f1= yz

    -+ y-z f

    2= z + ... f

    3= xz

    -+ ...

    After deleting equal rows G and J, the table becomes

    f2

    f3

    m6

    m1

    cost

    *2 B: x 1

    *3 C: x-y-

    3

    f1= yz

    -+ y

    -z f

    2= z + x f

    3= xz

    -+ x-y-

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    4.34.

    w x y z (a) (b) (c) (d) (e) (f)

    0 0 0 0 0 1 0 0 0 1

    0 0 0 1 0 0 1 0 0 0

    0 0 1 0 1 0 0 0 0 1

    0 0 1 1 1 1 1 0 1 0

    0 1 0 0 1 1 0 1 1 0

    0 1 0 1 1 1 0 0 1 1

    0 1 1 0 0 0 0 0 0 0

    0 1 1 1 0 0 0 1 1 0

    1 0 0 0 0 1 1 1 1 1

    1 0 0 1 0 1 1 0 0 1

    1 0 1 0 1 0 1 0 0 1

    1 0 1 1 0 1 1 0 1 1

    1 1 0 0 1 1 1 1 1 0

    1 1 0 1 1 1 0 1 1 1

    1 1 1 0 0 0 1 0 0 0

    1 1 1 1 0 0 1 1 1 1

    (a)

    f = x-yz-+ xy

    -+ w

    -x-y

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    4.34. (continued)

    f = (w-+x+z

    -)(x+y)(x

    -+y-) f = (w

    -+y-+z-)(x+y)(x

    -+y-)

    (b)

    f = x-yz + y

    -z-+ xy

    -+ wy

    -

    f = (y-+z)(w+x+y+z

    -)(x-+y-)

    (c)

    f = x-z + wz

    -+ wy

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    4.34. (continued)

    f = (w+z)(x-+y+z

    -)(w+x

    -)

    (d)

    f = xyz + xy-z-+ wy

    -z-+ wxy

    -f = xyz + xy

    -z-+ wy

    -z-

    + wxz

    f = (y-+z)(x+z

    -)(w+y+z

    -)(w+x)

    (e)

    f = yz + wy-z-+ xy

    -

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    4.34. (continued)

    f = (y-+z)(x+y+z

    -)(w+x+z) f = (y

    -+z)(x+y+z

    -)(w+x+y)

    (f)

    f = wz + xy-z + x

    -z-

    f = (x-+z)(w+x+z-)(w+x-+y-) f = (x-+z)(w+x+z-)(w+y-+z-)

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    4.35.

    w x y z (a) (b) (c) (d) (e)

    0 0 0 0 - - 0 0 0

    0 0 0 1 0 1 1 0 0

    0 0 1 0 1 0 - 0 1

    0 0 1 1 1 - - - 1

    0 1 0 0 - - 0 0 1

    0 1 0 1 1 1 1 1 0

    0 1 1 0 0 1 - 1 0

    0 1 1 1 0 1 1 1 -

    1 0 0 0 - 0 0 - 0

    1 0 0 1 0 1 0 - -

    1 0 1 0 - 0 1 0 1

    1 0 1 1 - 1 1 0 -

    1 1 0 0 1 1 0 1 0

    1 1 0 1 0 1 - 1 1

    1 1 1 0 1 0 0 1 1

    1 1 1 1 0 0 0 0 1

    (a)

    f = wz-+ x-y + w

    -xy-

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    4.35. (continued)

    f = (w-+z-)(x+y)(w+x

    -+y-)

    (b)

    f = x-z + w-x + xy-

    f = (x+z)(w-+x-+y-)

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    4.35. (continued)

    (c)

    f = w-z + x

    -y

    f = (w+z)(w-+x-)(w-+y)

    f = (y+z)(w-+x-)(w-+y)

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    4.35. (continued)

    (d)

    f = w-xz + xyz

    -+ wy

    -

    f = x(w+y+z)(w-+y-+z-)

    (e)

    f = wz + w-xy-z-+ wy + x

    -y

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    4.35. (continued)

    f = (w+x-+z-)(w-+y+z)(x+y)(w+x

    -+y-)

    f = (w+y+z-)(w-+y+z)(x+y)(w+x

    -+y-)

    4.36. (a)

    f = Ax-z + Bxz

    -+ x-yz

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    4.36. (continued)

    (b)

    f = Ay-+ B-x-z + Bx

    -y + xy

    -z-

    (c)

    f = ABz + Ayz + A-x-y

    4.37. (a)

    f = yz-+ w-y + xz

    -+ wx

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    4.37. (continued)

    (b)

    f = v-wy-z-+ vxyz

    -+ w-xz + v

    -xy-

    + v-wx

    (c)

    f = x-yz + vz

    -+ wy

    -z