_:nc066023167f347118de9b817657b0da5xb0
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.numerade.com/questions/compute-the-net-outward-flux-of-of-the-vector-field-mathbffx-mathbfiy-mathbfjz-mathbfk-leftx2y2z2rig/>