diff --git a/src_comb/Boost_bitset.h b/src_comb/Boost_bitset.h
index f9979db..eae4ac4 100644
--- a/src_comb/Boost_bitset.h
+++ b/src_comb/Boost_bitset.h
@@ -9,17 +9,6 @@
 #include <string>
 #include <vector>
 
-template <typename Tidx> std::vector<Tidx> FaceToVector(Face const &eSet) {
-  size_t nbVert = eSet.count();
-  std::vector<Tidx> eList(nbVert);
-  boost::dynamic_bitset<>::size_type aRow = eSet.find_first();
-  for (size_t i = 0; i < nbVert; i++) {
-    eList[i] = static_cast<Tidx>(aRow);
-    aRow = eSet.find_next(aRow);
-  }
-  return eList;
-}
-
 std::vector<int> FaceTo01vector(Face const &eSet) {
   size_t nbVert = eSet.size();
   size_t siz = eSet.count();
diff --git a/src_comb/Boost_bitset_kernel.h b/src_comb/Boost_bitset_kernel.h
index de84df1..e370f59 100644
--- a/src_comb/Boost_bitset_kernel.h
+++ b/src_comb/Boost_bitset_kernel.h
@@ -380,6 +380,38 @@ vectface sort_vectface(vectface const &vf) {
 
 vectface unicize_vectface(vectface const &vf) { return sort_vectface(vf); }
 
+template <typename Tidx> std::vector<Tidx> FaceToVector(Face const &eSet) {
+  size_t nbVert = eSet.count();
+  std::vector<Tidx> eList(nbVert);
+  boost::dynamic_bitset<>::size_type aRow = eSet.find_first();
+  for (size_t i = 0; i < nbVert; i++) {
+    eList[i] = static_cast<Tidx>(aRow);
+    aRow = eSet.find_next(aRow);
+  }
+  return eList;
+}
+
+void WriteVectfaceGAP(std::ostream& os, vectface const& vf) {
+  bool IsFirst = true;
+  os << "[";
+  for (auto &trig : vf) {
+    if (!IsFirst) {
+      os << ",\n";
+    }
+    IsFirst = false;
+    std::vector<size_t> eList = FaceToVector<size_t>(trig);
+    os << StringStdVectorGAP(eList);
+  }
+  os << "]";
+}
+
+std::string StringVectfaceGAP(vectface const& vf) {
+  std::ostringstream os;
+  WriteVectfaceGAP(os, vf);
+  return os.str();
+}
+
+
 /*
 template<>
 void std::swap(Face & x, Face & y)