reserve G for _Graph;
reserve G2 for _Graph, G1 for Supergraph of G2;
reserve V for set;

theorem Th88:
  for G2, V for G1 being addVertices of G2, V
  holds G2 is inducedSubgraph of G1, the_Vertices_of G2
proof
  let G2, V;
  let G1 be addVertices of G2, V;
  set V2 = the_Vertices_of G2;
  reconsider G3=G2 as Subgraph of G1 by Th61;
  A2: the_Vertices_of G3 = V2;
  A3: the_Edges_of G3 = the_Edges_of G1 by Def10
    .= G1.edgesBetween(V2) by Th85;
  thus G2 is inducedSubgraph of G1, V2 by A2, A3, GLIB_000:def 37;
end;
