Jump part of a BV derivative
= Jump part of a BV derivative
{title2=$D^ju=(u^+-u^-)\nu_u\,\mathcal H^{n-1}\!\lfloor J_u$}
This <derivative> component is carried by the <jump set of a BV function>. Swapping the two <BV traces on a hypersurface> and reversing the normal leaves it unchanged. In one dimension it consists of the point <measure atoms>, each weighted by the difference between the right and left limits.