ブラウザの設定でJava Scriptの使用を有効にしてご利用ください。
出典:Wikipedia
出典:『Wikipedia』 (2011/06/15 08:28 UTC 版)
In mathematics, a binary relation R over a set X is symmetric if it holds for all a and b in X that if a is related to b then b is related to a.
Symmetric relation