Removes nodes or marks nodes for removal points or removes elements from a mesh.   The first option sets the node type flag  [itp=ifitpdud (21)] to indicate that the set of nodes are treated as invisible, but does not actually remove the nodes.  Elements will also be removed.  If  inclusive is specified, any element containing a marked node will be removed.  If  exclusive is specified (default), any element containing a retained node is retained.  The second option, compress, removes the invisible nodes (i.e. those nodes whose itp1 value is 21) from the data structure and material-wise resequences all remaining nodes.  The third option, zero_volume, will remove elements whose volumes are less than or equal to the specified threshold.  The fourth option, element, will remove all marked elements from the mesh.  Marked elements have a negative value for the first entry in the itet vertex list.  The fifth option will remove a specified list of elements from the mesh.  The sixth option will remove elements that are specified in a named element set from the mesh. The seventh option, womesh will delete stray nodes that are not connected to any element and that are not parent nodes.
FORMAT: rmpoint/ifirst,ilast,istride/[exclusive|inclusive ]
rmpoint/element/tet list
  rmpoint/pset, get, pset1
    mark all the nodes in pset1 for removal.  Remove elements all of whose vertices are members of pset1.
    remove all marked nodes and correct the itet array
     remove all elements with volumes less than 1.e-16
rmpoint/element/27 259 1009
     remove the three specified elements
rmpoint/element/eltset, get, myeset