{
  //TProof::Open("");
  // create a TChain instead of a TTree
  TChain *chain = new TChain("tree", "particle tree");
  // add our file
  TFileCollection *fc=new TFileCollection("fc","alldata","list_small.txt");
  chain->AddFileInfoList(fc->GetList());
  // chain->Print();
  // I also tried ...
  //chain->Add("tree_096_1.root");
  // without success

  // tell the chain that we want to use PROOF
  //chain->SetProof();
  // run the selector
  chain->Process("mytree.C+");

}