平成31年度 春期 応用情報技術者試験 午前 問23

• 左側回路の特徴: 左側の回路は論理積（AND）素子のみで構成されています。
• E = A AND (B AND C)

• F = D AND (B AND C)

• 右側回路の特徴: 右側の回路は論理和（OR）素子で構成されています。

• E = A OR (B OR C)
• F = D OR (B OR C)

各選択肢の検証

• ア:
  入力: A = 0, B = 0, C = 0, D = 0
  左回路:
• E = 0 AND (0 AND 0) = 0
• F = 0 AND (0 AND 0) = 0
  右回路:
• E = 0 OR (0 OR 0) = 0

• F = 0 OR (0 OR 0) = 0
  → 両方で成立

• イ:
  入力: A = 0, B = 1, C = 1, D = 1
  左回路:

• E = 0 AND (1 AND 1) = 0
• F = 1 AND (1 AND 1) = 1
  右回路:
• E = 0 OR (1 OR 1) = 1

• F = 1 OR (1 OR 1) = 1
  → 不一致（左側のみ成立）

• ウ:
  入力: A = 1, B = 1, C = 0, D = 1
  左回路:

• E = 1 AND (1 AND 0) = 0
• F = 1 AND (1 AND 0) = 0
  右回路:
• E = 1 OR (1 OR 0) = 1

• F = 1 OR (1 OR 0) = 1
  → 不一致（左側のみ成立）

• エ:
  入力: A = 1, B = 1, C = 1, D = 1
  左回路:

• E = 1 AND (1 AND 1) = 1
• F = 1 AND (1 AND 1) = 1
  右回路:
• E = 1 OR (1 OR 1) = 1
• F = 1 OR (1 OR 1) = 1
  → 両方で成立

答え

ウ: A = 1, B = 1, C = 0, D = 1 で出力 E = 0, F = 0 が成立