
theorem
  for G1 being edgeless _Graph, G2 being Subgraph of G1
  holds G1 is addVertices of G2, the_Vertices_of G1 \ the_Vertices_of G2
proof
  let G1 be edgeless _Graph, G2 be Subgraph of G1;
  A1: the_Edges_of G1 = the_Edges_of G2;
  G1 is Supergraph of G2 by GLIB_006:57;
  hence thesis by A1, Th33;
end;
