Best guess: [itex]\lim_{x \rightarrow a}f(x) \neq L[/itex] means, given there exists [itex]\epsilon > 0[/itex] there exists [itex]\delta > 0[/itex] such that [itex]|x-a|<\delta \Rightarrow |f(x) - L| > \epsilon[/itex]. I'm really not sure about this, however.