diff --git a/src/problem/problem.cpp b/src/problem/problem.cpp
index 49f59f9c89cbcfa2e12be380ec4fc73ee60dda5a..3e9abf1ea460f7ccc4aeea29dc65de3425c20dba 100644
--- a/src/problem/problem.cpp
+++ b/src/problem/problem.cpp
@@ -1113,7 +1113,7 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
         {
             if (_verbose)
             {
-                _stream << "    <- c" << cby->id() << " -> ";
+                _stream << "    <- Fac" << cby->id() << " -> ";
                 for (const auto& Fow : cby->getFrameOtherList())
                     _stream << " F" << Fow.lock()->id() << std::endl;
             }
@@ -1187,9 +1187,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
             {
                 if (_verbose)
                 {
-                    _stream << "      <- c" << cby->id() << " -> ";
+                    _stream << "      <- Fac" << cby->id() << " -> ";
                     for (const auto& Cow : cby->getCaptureOtherList())
-                        _stream << " C" << Cow.lock()->id();
+                        _stream << " Cap" << Cow.lock()->id();
                     _stream << std::endl;
                 }
 
@@ -1242,9 +1242,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                 {
                     if (_verbose)
                     {
-                        _stream << "        <- c" << cby->id() << " -> ";
+                        _stream << "        <- Fac" << cby->id() << " -> ";
                         for (const auto& fow : cby->getFeatureOtherList())
-                            _stream << " f" << fow.lock()->id();
+                            _stream << " Ftr" << fow.lock()->id();
                         _stream << std::endl;
                     }
 
@@ -1278,9 +1278,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             const auto& Fo = Fow.lock();
                             if (_verbose)
                             {
-                                _stream << " ( --> F" << Fo->id() << " <- ";
+                                _stream << " ( --> Frm" << Fo->id() << " <- ";
                                 for (auto cby : Fo->getConstrainedByList())
-                                    _stream << " c" << cby->id();
+                                    _stream << " Fac" << cby->id();
                             }
 
                             // check constrained_by pointer in constrained frame
@@ -1303,9 +1303,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
 
                             if (_verbose)
                             {
-                                _stream << " ( --> C" << Co->id() << " <- ";
+                                _stream << " ( --> Cap" << Co->id() << " <- ";
                                 for (auto cby : Co->getConstrainedByList())
-                                    _stream << " c" << cby->id();
+                                    _stream << " Fac" << cby->id();
                             }
 
                             // check constrained_by pointer in constrained frame
@@ -1327,9 +1327,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             const auto& fo = fow.lock();
                             if (_verbose)
                             {
-                                _stream << " ( --> f" << fo->id() << " <- ";
+                                _stream << " ( --> Ftr" << fo->id() << " <- ";
                                 for (auto cby : fo->getConstrainedByList())
-                                    _stream << " c" << cby->id();
+                                    _stream << " Fac" << cby->id();
                             }
 
                             // check constrained_by pointer in constrained feature
@@ -1351,9 +1351,9 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
 
                             if (_verbose)
                             {
-                                _stream << " ( --> L" << Lo->id() << " <- ";
+                                _stream << " ( --> Lmk" << Lo->id() << " <- ";
                                 for (auto cby : Lo->getConstrainedByList())
-                                    _stream << " c" << cby->id();
+                                    _stream << " Fac" << cby->id();
                             }
 
                             // check constrained_by pointer in constrained landmark
@@ -1406,12 +1406,12 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
 
                         // find in own Frame
                         found_here  = F->hasStateBlock(sb);
-                        if (found_here && _verbose) _stream << " F" << F->id();
+                        if (found_here && _verbose) _stream << " Frm" << F->id();
                         found       = found || found_here;
 
                         // find in own Capture
                         found_here  = C->hasStateBlock(sb);
-                        if (found_here && _verbose) _stream << " C" << C->id();
+                        if (found_here && _verbose) _stream << " Cap" << C->id();
                         found       = found || found_here;
 
                         // Find in other Captures of the own Frame
@@ -1419,7 +1419,7 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             for (auto FC : F->getCaptureList())
                             {
                                 found_here  = FC->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " F" << F->id() << ".C" << FC->id();
+                                if (found_here && _verbose) _stream << " Frm" << F->id() << ".Cap" << FC->id();
                                 found       = found || found_here;
                             }
 
@@ -1427,7 +1427,7 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                         if (S)
                         {
                             found_here  = S->hasStateBlock(sb);
-                            if (found_here && _verbose) _stream << " S" << S->id();
+                            if (found_here && _verbose) _stream << " Sen" << S->id();
                             found       = found || found_here;
                         }
 
@@ -1439,14 +1439,14 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             {
                                 const auto& Fo = Fow.lock();
                                 found_here  = Fo->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " Fo" << Fo->id();
+                                if (found_here && _verbose) _stream << " FrmO" << Fo->id();
                                 found       = found || found_here;
 
                                 // find in feature other's captures
                                 for (auto FoC : Fo->getCaptureList())
                                 {
                                     found_here  = FoC->hasStateBlock(sb);
-                                    if (found_here && _verbose) _stream << " Fo" << Fo->id() << ".C" << FoC->id();
+                                    if (found_here && _verbose) _stream << " FrmO" << Fo->id() << ".C" << FoC->id();
                                     found       = found || found_here;
                                 }
 
@@ -1460,7 +1460,7 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             {
                                 const auto& Co = Cow.lock();
                                 found_here  = Co->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " Co" << Co->id();
+                                if (found_here && _verbose) _stream << " CapO" << Co->id();
                                 found       = found || found_here;
                             }
                         }
@@ -1474,19 +1474,19 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                                 // find in constrained feature's Frame
                                 auto foF    = fo->getFrame();
                                 found_here  = foF->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " foF" << foF->id();
+                                if (found_here && _verbose) _stream << " FtrOF" << foF->id();
                                 found       = found || found_here;
 
                                 // find in constrained feature's Capture
                                 auto foC    = fo->getCapture();
                                 found_here  = foC->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " foC" << foC->id();
+                                if (found_here && _verbose) _stream << " FtrOC" << foC->id();
                                 found       = found || found_here;
 
                                 // find in constrained feature's Sensor
                                 auto foS    = fo->getCapture()->getSensor();
                                 found_here  = foS->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " foS" << foS->id();
+                                if (found_here && _verbose) _stream << " FtrOS" << foS->id();
                                 found       = found || found_here;
                             }
                         }
@@ -1498,7 +1498,7 @@ bool Problem::check(bool _verbose, std::ostream& _stream) const
                             {
                                 const auto& Lo = Low.lock();
                                 found_here  = Lo->hasStateBlock(sb);
-                                if (found_here && _verbose) _stream << " Lo" << Lo->id();
+                                if (found_here && _verbose) _stream << " LmkO" << Lo->id();
                                 found       = found || found_here;
                             }
                         }