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次へ: 最小項を最大項へ変換 上へ: 特別講義2 問題1の解答例 戻る: 最大項

証明問題

次の式を証明しなさい。

$\displaystyle \sim (xy \lor \sim x z) = m_0 \lor m_2 \lor m_4 \lor m_5
$


証明法1

$\displaystyle \sim (xy \lor \sim x z)$ $\displaystyle =$ $\displaystyle (\sim x \lor \sim y)(x \lor \sim z)$  
  $\displaystyle =$ $\displaystyle \sim x x \lor \sim x \sim z \lor \sim y x
\lor \sim y \sim z$  
  $\displaystyle =$ $\displaystyle \sim x \sim z \lor \sim y x \lor \sim y
\sim z$  
  $\displaystyle =$ $\displaystyle \sim x \sim z (\sim y \lor y)$  
    $\displaystyle \lor \sim y x (\sim z \lor z)$  
    $\displaystyle \lor \sim y \sim z (\sim x \lor x)$  
  $\displaystyle =$ $\displaystyle \sim x \sim z \sim y \lor \sim x \sim z y$  
    $\displaystyle \lor \sim y x \sim z \lor \sim y x z$  
    $\displaystyle \lor \sim y \sim z \sim x \lor \sim y \sim
z x$  
  $\displaystyle =$ $\displaystyle \sim x \sim y \sim z \lor \sim x y \sim z$  
    $\displaystyle \lor x \sim y \sim z \lor x \sim y z$  
    $\displaystyle \lor \sim x \sim y \sim z \lor x \sim y
\sim z$  
  $\displaystyle =$ $\displaystyle m_0 \lor m_2 \lor m_4 \lor m_5 \lor m_0
\lor m_4$  
  $\displaystyle =$ $\displaystyle m_0 \lor m_2 \lor m_4 \lor m_5$  

証明法2

$\displaystyle \sim (xy \lor \sim x z)$ $\displaystyle =$ $\displaystyle (\sim x \lor \sim y)(x \lor \sim z)$  
  $\displaystyle =$ $\displaystyle (\sim x \lor \sim y \lor \sim z z)(x \lor
\sim z \lor \sim y y)$  
  $\displaystyle =$ $\displaystyle (\sim x \lor \sim y \lor \sim z)(\sim x
\lor \sim y \lor z)$  
    $\displaystyle \land (x \lor \sim z \lor \sim y)(x \lor
\sim z \lor y)$  
  $\displaystyle =$ $\displaystyle (\sim x \lor \sim y \lor \sim z)(\sim x
\lor \sim y \lor z)$  
    $\displaystyle \land (x \lor \sim y \lor \sim z)(x \lor
y \lor \sim z)$  
  $\displaystyle =$ $\displaystyle M_0 M_1 M_4 M_6$  


$\displaystyle \sim (xy \lor \sim x z)$ $\displaystyle =$ $\displaystyle M_0 M_1 M_4 M_6$  
  $\displaystyle =$ $\displaystyle \sim \sim (M_0 M_1 M_4 M_6)$  
  $\displaystyle =$ $\displaystyle \sim(\sim M_0 \lor \sim M_1 \lor \sim M_4
\lor \sim M_6)$  
  $\displaystyle =$ $\displaystyle \sim(m_7 \lor m_6 \lor m_3 \lor m_1)$  
  $\displaystyle =$ $\displaystyle m_0 \lor m_2 \lor m_4 \lor m_5$   $\displaystyle \mbox{$\because$\ 原関数に含まれないもの}$  


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次へ: 最小項を最大項へ変換 上へ: 特別講義2 問題1の解答例 戻る: 最大項
MANOME Yoichi 平成17年6月17日