Let $\nu$ be a Borel measure on $\mathbb R^n$ (i.e. the underlying measure space is $(\mathbb R^n, \mathcal B, \nu)$). The symmetric derivative of $\nu$ at $x \in \mathbb R^n$ is \((D\nu)(x) = \lim_{r\to 0} \frac{\nu(B(x,r))}{\mu(B(x,r))}\) if this limit exists. This is the derivative ( todo: link to 208 notions?) in the symmetric differential basis.
Wikidata ID: Q3773126