contraposition
対偶
reductio ad absurdum
/suto3/google.iconcontraposition
/suto3/Google画像検索.iconcontraposition
/suto3/Google定義検索.icon contraposition
/suto3/wikipedia.iconcontraposition
/suto3/weblio.icon contraposition
/suto3/kotobank.icon contraposition
/suto3/jisho.icon contraposition