(オリジナルポスト)
https://qiita.com/wakiyo1017/items/80461451bbf26c0abf1c
SymPy Liveで
(参考)
https://ja.stackoverflow.com/questions/72753/sympy-liveの和集合unionの正しい使い方を教えて下さい
WolframAlphaで
入力
和集合[{"A", "D", "A", "G", "B", "C", "B"}]
https://www.wolframalpha.com/input/?i=%E5%92%8C%E9%9B%86%E5%90%88%5B%7B%22A%22%2C+%22D%22%2C+%22A%22%2C+%22G%22%2C+%22B%22%2C+%22C%22%2C+%22B%22%7D%5D&lang=ja
出力
A | B | C | D | G
