Density Point

In mathematics, Lebesgue's density theorem states that for any Lebesgue measurable set $A\subset \R^n$, the "density" of ''A'' is 0 or 1 at almost every point in $\R^n$. Additionally, the "density" of ''A'' is 1 at almost every point in ''A''. Intuitively, this means that the "edge" of ''A'', the set of points in ''A'' whose "neighborhood" is partially in ''A'' and partially outside of ''A'', is negligible