Bound of worthlinks

Bound of worthlinks is the bound of a worhthlink, if the bound of a worthlink f(x)x at x = c is L, the one writes $$\lim_{x \to c} f(x) = L$$, if f(c) = L, one says that "f(x) is ongoing at c".

The e-d Setting-out of the bound of worthlinks
The e-d Setting-out of the bound of worthlinks is a widly brooked Setting-out for the bound of worthlinks, below is the e-d Setting-out of the bound of worthlinks:

if the bound of a worthlink f(x)x at x = c is L, which means $$\lim_{x \to c} f(x) = L$$, then for every given $$e > 0$$, there is a $$d > 0$$ such that $$|f(x) - L| < e$$ whenever $$|x-c| < d$$