diff --git a/multipers/gudhi/gudhi/Multi_critical_filtration.h b/multipers/gudhi/gudhi/Multi_critical_filtration.h
index d76f32d..588f5c4 100644
--- a/multipers/gudhi/gudhi/Multi_critical_filtration.h
+++ b/multipers/gudhi/gudhi/Multi_critical_filtration.h
@@ -858,23 +858,37 @@ class Multi_critical_filtration {
   bool _generator_can_be_added(const Generator &x, std::size_t curr, std::size_t &end) {
     if (x.empty() || x.is_nan()) return false;
 
-    if constexpr (co){
-      if (x.is_minus_inf() && end - curr != 0) return false;
-      
+    // assumes that everything between curr and end is simplified
+    // so, only multi_filtration_[curr] can be at inf or -inf.
+    if constexpr (co) {
+      if (multi_filtration_[curr].is_plus_inf() || (x.is_minus_inf() && end - curr != 0)) {
+        return false;
+      }
+      if (multi_filtration_[curr].is_minus_inf()) {
+        if (x.is_minus_inf()) {
+          return false;
+        }
+        end = curr;
+        return true;
+      }
       if (x.is_plus_inf()) {
-        if (end - curr == 1 && multi_filtration_[curr].is_plus_inf()) return false;
-        // assumes that everything between curr and end is already simplified
-        // so, if end - curr != 1, there can be no minus_inf anymore.
+        if (multi_filtration_[curr].is_plus_inf()) return false;
         end = curr;
         return true;
       }
     } else {
-      if (x.is_plus_inf() && end - curr != 0) return false;
-
+      if (multi_filtration_[curr].is_minus_inf() || (x.is_plus_inf() && end - curr != 0)) {
+        return false;
+      }
+      if (multi_filtration_[curr].is_plus_inf()) {
+        if (x.is_plus_inf()) {
+          return false;
+        }
+        end = curr;
+        return true;
+      }
       if (x.is_minus_inf()) {
-        if (end - curr == 1 && multi_filtration_[curr].is_minus_inf()) return false;
-        // assumes that everything between curr and end is already simplified
-        // so, if end - curr != 1, there can be no minus_inf anymore.
+        if (multi_filtration_[curr].is_minus_inf()) return false;
         end = curr;
         return true;
       }
diff --git a/multipers/multiparameter_module_approximation/approximation.h b/multipers/multiparameter_module_approximation/approximation.h
index fa6d7f3..1f70e1c 100644
--- a/multipers/multiparameter_module_approximation/approximation.h
+++ b/multipers/multiparameter_module_approximation/approximation.h
@@ -599,6 +599,7 @@ Module<value_type> multiparameter_module_approximation(
      */
     /* threshold, box); */
   }
+  
   out.add_barcode(current_line, barcode, threshold);
 
   if (verbose) std::cout << "Instantiated " << num_bars << " summands" << std::endl;
@@ -708,10 +709,7 @@ inline void Module<value_type>::add_barcode(
     const Line<value_type> &line,
     const std::vector<std::pair<int, std::pair<value_type, value_type>>> &barcode,
     const bool threshold_in) {
-  assert(barcode.size() != module_.size() &&
-         std::string("Barcode sizes doesn't match. Module is " + std::to_string(module_.size()) + " and barcode is " +
-                     std::to_string(barcode.size()))
-             .data());
+  assert(barcode.size() == module_.size() && "Barcode sizes doesn't match.");
 
   auto count = 0U;
   for (const auto &extBar : barcode) {
@@ -724,10 +722,7 @@ template <typename value_type>
 inline void Module<value_type>::add_barcode(const Line<value_type> &line,
                                             const std::vector<std::pair<value_type, value_type>> &barcode,
                                             const bool threshold_in) {
-  assert(barcode.size() != module_.size() &&
-         std::string("Barcode sizes doesn't match. Module is " + std::to_string(module_.size()) + " and barcode is " +
-                     std::to_string(barcode.size()))
-             .data());
+  assert(barcode.size() == module_.size() && "Barcode sizes doesn't match.");
 
   auto count = 0U;
   for (const auto &bar : barcode) {