522 Continuous
f is continuous at c if and only if for every ε>0 there exists δ>0 such that |x−c|<δ ⇒ |f(x)−f(c)|<ε. ┆「f(x) Ƚx→c」 = f(c)┆ ...
http://qindex.info/i.php?x=9756

-