reserve G for _Graph;
reserve V for non empty set, E for Relation of V;
reserve E for symmetric Relation of V;
reserve G for GraphFromSymRel of V, E;

theorem
  G is complete implies E is connected
proof
  assume G is complete;
  then createGraph(V,E) is complete; :: because of removeParallelEdges
  hence E is connected by Th69;
end;
