• The image part of the direct image with compact support $f_{!}\webleft (U\webright )$ of $U$ is the set $f_{!,\text{im}}\webleft (U\webright )$ defined by
    \begin{align*} f_{!,\text{im}}\webleft (U\webright ) & \mathrel {\smash {\overset {\mathclap {\scriptscriptstyle \text{def}}}=}}f_{!}\webleft (U\webright )\cap \mathrm{Im}\webleft (f\webright )\\ & = \webleft\{ b\in B\ \middle |\ \text{we have $f^{-1}\webleft (b\webright )\subset U$ and $f^{-1}\webleft (b\webright )\neq \emptyset $}\webright\} .\end{align*}

Noticed something off, or have any comments? Feel free to reach out!


You can also use the contact form below: