
theorem Th59:
  for G1, G2 being _Graph, H being Subgraph of G1,
    F being PGraphMapping of G1, G2
  holds dom (F|H)_V = dom F_V /\ the_Vertices_of H &
    dom (F|H)_E = dom F_E /\ the_Edges_of H by RELAT_1:61;
