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diff --git a/src/Persistent_cohomology/example/plain_homology.cpp b/src/Persistent_cohomology/example/plain_homology.cpp
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+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Marc Glisse
+ *
+ *    Copyright (C) 2015 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <iostream>
+#include <vector>
+#include <cstdint>  // for std::uint8_t
+
+/* We could perfectly well use the default Simplex_tree<> (which uses
+ * Simplex_tree_options_full_featured), the following simply demonstrates
+ * how to save on storage by not storing a filtration value.  */
+
+struct MyOptions : Gudhi::Simplex_tree_options_full_featured {
+  // Implicitly use 0 as filtration value for all simplices
+  static const bool store_filtration = false;
+  // The persistence algorithm needs this
+  static const bool store_key = true;
+  // I have few vertices
+  typedef short Vertex_handle;
+  // Maximum number of simplices to compute persistence is 2^8 - 1 = 255. One is reserved for null_key
+  typedef std::uint8_t Simplex_key;
+};
+
+using ST = Gudhi::Simplex_tree<MyOptions>;
+using Field_Zp = Gudhi::persistent_cohomology::Field_Zp;
+using Persistent_cohomology = Gudhi::persistent_cohomology::Persistent_cohomology<ST, Field_Zp>;
+
+int main() {
+  ST st;
+
+  /* Complex to build. */
+  /*    1   3   5      */
+  /*    o---o---o      */
+  /*   / \ /           */
+  /*  o---o   o        */
+  /*  2   0   4        */
+
+  const short edge01[] = {0, 1};
+  const short edge02[] = {0, 2};
+  const short edge12[] = {1, 2};
+  const short edge03[] = {0, 3};
+  const short edge13[] = {1, 3};
+  const short edge35[] = {3, 5};
+  const short vertex4[] = {4};
+  st.insert_simplex_and_subfaces(edge01);
+  st.insert_simplex_and_subfaces(edge02);
+  st.insert_simplex_and_subfaces(edge12);
+  st.insert_simplex_and_subfaces(edge03);
+  st.insert_simplex(edge13);
+  st.insert_simplex_and_subfaces(edge35);
+  st.insert_simplex(vertex4);
+
+  // Sort the simplices in the order of the filtration
+  st.initialize_filtration();
+
+  // Class for homology computation
+  // By default, since the complex has dimension 1, only 0-dimensional homology would be computed.
+  // Here we also want persistent homology to be computed for the maximal dimension in the complex (persistence_dim_max = true)
+  Persistent_cohomology pcoh(st, true);
+
+  // Initialize the coefficient field Z/2Z for homology
+  pcoh.init_coefficients(2);
+
+  // Compute the persistence diagram of the complex
+  pcoh.compute_persistent_cohomology();
+
+  // Print the result. The format is, on each line: 2 dim 0 inf
+  // where 2 represents the field, dim the dimension of the feature.
+  // 2  0 0 inf
+  // 2  0 0 inf
+  // 2  1 0 inf
+  // 2  1 0 inf
+  // means that in Z/2Z-homology, the Betti numbers are b0=2 and b1=2.
+  pcoh.output_diagram();
+
+  // Print the Betti numbers are b0=2 and b1=2.
+  std::cout << std::endl;
+  std::cout << "The Betti numbers are : ";
+  for (int i = 0; i < 3; i++)
+    std::cout << "b" << i << " = " << pcoh.betti_number(i) << " ; ";
+  std::cout << std::endl;
+}