diff --git a/examples/petrinet/models/m_example_mutex.od b/examples/petrinet/models/m_example_mutex.od
new file mode 100644
index 0000000..75cc67b
--- /dev/null
+++ b/examples/petrinet/models/m_example_mutex.od
@@ -0,0 +1,30 @@
+# from slides:
+#   http://msdl.uantwerpen.be/people/hv/teaching/MoSIS/lectures/presentation.PetriNets.pdf
+#   page 51
+
+general_1:Place
+general_2:Place
+critical_1:Place
+critical_2:Place
+semaphore:Place
+
+enterCritical_1:Transition
+leaveCritical_1:Transition
+enterCritical_2:Transition
+leaveCritical_2:Transition
+
+:arc (general_1 -> enterCritical_1)
+:arc (semaphore -> enterCritical_1)
+:arc (enterCritical_1 -> critical_1)
+
+:arc (critical_1 -> leaveCritical_1)
+:arc (leaveCritical_1 -> semaphore)
+:arc (leaveCritical_1 -> general_1)
+
+:arc (semaphore -> enterCritical_2)
+:arc (general_2 -> enterCritical_2)
+:arc (enterCritical_2 -> critical_2)
+
+:arc (leaveCritical_2 -> semaphore)
+:arc (leaveCritical_2 -> general_2)
+:arc (critical_2 -> leaveCritical_2)
\ No newline at end of file
diff --git a/examples/petrinet/models/m_example_mutex_rt_initial.od b/examples/petrinet/models/m_example_mutex_rt_initial.od
new file mode 100644
index 0000000..83efc8c
--- /dev/null
+++ b/examples/petrinet/models/m_example_mutex_rt_initial.od
@@ -0,0 +1,25 @@
+general_1_s:PlaceState {
+  numTokens = 1;
+}
+
+general_2_s:PlaceState {
+  numTokens = 1;
+}
+
+critical_1_s:PlaceState {
+  numTokens = 0;
+}
+
+critical_2_s:PlaceState {
+  numTokens = 0;
+}
+
+semaphore_s:PlaceState {
+  numTokens = 1;
+}
+
+:of (general_1_s -> general_1)
+:of (general_2_s -> general_2)
+:of (critical_1_s -> critical_1)
+:of (critical_2_s -> critical_2)
+:of (semaphore_s -> semaphore)
diff --git a/examples/petrinet/runner.py b/examples/petrinet/runner.py
index d7995c8..ece1e9e 100644
--- a/examples/petrinet/runner.py
+++ b/examples/petrinet/runner.py
@@ -23,8 +23,10 @@ if __name__ == "__main__":
     # Read models from their files
     mm_cs           =         read_file('metamodels/mm_design.od')
     mm_rt_cs        = mm_cs + read_file('metamodels/mm_runtime.od')
-    m_cs            =         read_file('models/m_example_simple.od')
-    m_rt_initial_cs = m_cs +  read_file('models/m_example_simple_rt_initial.od')
+    # m_cs            =         read_file('models/m_example_simple.od')
+    # m_rt_initial_cs = m_cs +  read_file('models/m_example_simple_rt_initial.od')
+    m_cs            =         read_file('models/m_example_mutex.od')
+    m_rt_initial_cs = m_cs +  read_file('models/m_example_mutex_rt_initial.od')
 
     # Parse them
     mm           = loader.parse_and_check(state, mm_cs,           scd_mmm, "Petri-Net Design meta-model")