Convergence of a Net

A Net f : D X : 𝑓 𝐷 𝑋 f:D\to X in a Topological Space X 𝑋 X converges to a point x 𝑥 x if for every Open Neighborhood U 𝑈 U of x 𝑥 x , the net f 𝑓 f Eventually lies within U 𝑈 U .

Explicitly, this means that: