event structure
事象構造、イベント構造、イベントストラクチャ
binary relation
Mathematical structure
https://source.unsplash.com/featured/?event-structure#.png
/suto3/google.iconevent structure
/suto3/Google画像検索.iconevent structure
/suto3/Google定義検索.icon event structure
/suto3/wikipedia.iconevent structure
/suto3/weblio.icon event structure
/suto3/kotobank.icon event structure
/suto3/jisho.icon event structure