Is statement about limits? I'm a bit ignorant but I thought the limit was defined as:

A function f has limit L at a, if ∀ε> 0 ∃δ> 0: ∀x (0 < |x - a| <δ⇒ |f (x) - L| <ε)

Your statement seems to say that for the real number x and real numberδthere exists a real number such that for each y if the absolute value of the difference between x and y is less thanδ, then the absolute value of the squares of x and y is less than....