diff --git a/Train/TwoTrains.svg b/Train/TwoTrains.svg
index 988efb4b1f4fdd42dbefc245cf1c926eeffc1c62..ce510a0a8cc90f2c95088f9d2b3109e6e1b49cbc 100644
--- a/Train/TwoTrains.svg
+++ b/Train/TwoTrains.svg
@@ -2,8 +2,8 @@
 <svg
    xmlns="http://www.w3.org/2000/svg"
    width="900"
-   height="400"
-   viewBox="5 15 150 30"
+   height="200"
+   viewBox="5 15 150 20"
    version="1.1"
    id="svg5154">
 
@@ -25,8 +25,8 @@
             fill : lightgray
         }
         .train-hover {
-            fill : red;
-            stroke-width: 0.5;
+            fill : rosybrown;
+            stroke-width: 0.35;
             stroke : black;
         }
         .train-back {
@@ -40,13 +40,18 @@
             fill : green
         }
         .green-ma {
-            fill : lightgreen;
+            fill : khaki;
             stroke : none;
             stroke-width: 0.1;
             opacity: 1.0
         }
    </style>
    
+  <polygon id = "ma_polygon"
+       points="0,0 0,2 10,2 10,0 70,0 70,1 90,1 90,0"
+       class = "green-ma"
+       transform="translate(10,19.25)" />
+
     <polygon id = "train_polygon_tr1"
        points="0,0 100,0"
        class="train-normal"
@@ -88,10 +93,6 @@
        stroke="gray" fill="none"
        transform="translate(10,22.5)" />
        
-  <polygon id = "ma_polygon"
-       points="0,0 0,2 10,2 10,0 70,0 70,1 90,1 90,0"
-       class = "green-ma"
-       transform="translate(10,19.5)" />
        
   <rect id = "ttd_rect"
        style="stroke-width: 0.1"
diff --git a/Train/TwoTrainsMA.json b/Train/TwoTrainsMA.json
index 508fe86a41d921fe4a556d523efbc5e0b95e058a..610b0ef50ed09edb09cf9fafd10e680c210ced1f 100644
--- a/Train/TwoTrainsMA.json
+++ b/Train/TwoTrainsMA.json
@@ -28,7 +28,7 @@
       "id":"train_back_%0",
       "attr":"class",
       "value":"IF %0 : dom(train_ma) THEN \"train-back-connected\" ELSE \"train-back\" END",
-      "comment":"show train back polygon"
+      "comment":"colour train back polygon"
     },
     {
 	  "repeat": ["tr1","tr2"],
@@ -41,7 +41,7 @@
 	  "repeat": ["tr1","tr2"],
       "id":"train_info_text_%0",
       "attr":"text",
-      "value":"\"Train %0: \" ^ TO_STRING(train_rear_end(%0)) ^ \"..\" ^ TO_STRING(train_rear_end(%0)+train_length(%0))",
+      "value":"\"Train %0 is at \" ^ TO_STRING(train_rear_end(%0)) ^ \"..\" ^ TO_STRING(train_front_end(%0)) ^ IF %0:dom(train_ma) THEN  \" with MA until \" ^ TO_STRING(train_ma(%0)) ELSE \" and has no MA\" END",
       "comment":"adapt info field of train"
     },
     
@@ -72,21 +72,21 @@
     {
       "id":"ma_polygon",
       "attr":"points",
-      "value":"svg_set_polygon(train_ma_all,100.0/real(TrackElementNumber+1),100.0,0.5)",
+      "value":"svg_set_polygon(train_ma_all,100.0/real(TrackElementNumber+1),100.0,0.75)",
       "comment":"show MA reserved zones"
     }
     ],
   "events":[ 
     {
       "id":"occupied_ttd_polygon",
-      "event":"TTD_Free",
+      "event":"TrainAcceptsFirstMA",
       "optional" : true,
       "hovers": [{ "attr":"stroke", "enter":"black", "leave":"none"},
                  { "attr":"opacity", "enter":"0.5", "leave":"1.0"}]
     },
     {
       "id":"cleared_ttd_polygon",
-      "event":"TTD_Occupied_By_Train",
+      "event":"TrainAcceptsNewMA",
       "optional" : true,
       "hovers": [{ "attr":"stroke", "enter":"black", "leave":"none"},
                  { "attr":"opacity", "enter":"0.5", "leave":"1.0"}]
diff --git a/Train/TwoTrainsMA.mch b/Train/TwoTrainsMA.mch
index 5348d5afa1aaa6234c2f62e6013b4f8703fac8bb..1e3d418f2a11babe2ea17e7fb143a359aebdb340 100644
--- a/Train/TwoTrainsMA.mch
+++ b/Train/TwoTrainsMA.mch
@@ -45,17 +45,19 @@ OPERATIONS
   
   TrainAcceptsNewMA(tr,newMA) = PRE tr:dom(train_ma) & newMA:TRACK & newMA > train_ma(tr) &
       !(t2).(t2 /= tr => train_ma(tr)..newMA /\ train_reserved(t2) = {}) /*@desc "MA extension is safe" */ 
-     // !(ttd).(ttd:occ => train_ma(tr)..newMA
+     // TODO: use TTD info !(ttd).(ttd:occ => train_ma(tr)..newMA
       THEN
      train_ma(tr) := newMA
   END;
   
   TrainMoveForward(tr,new_front) = PRE tr:dom(train_ma) & 
-                                       new_front = train_rear_end(tr) + train_length(tr) + 1 & //buggy
-                                       new_front:TRACK &  new_front < train_ma(tr) THEN
+                                      // new_front = train_rear_end(tr) + train_length(tr) + 1 & //buggy
+                                       new_front = train_front_end(tr) + 1 & //correct
+                                       new_front:TRACK &  new_front < train_ma(tr) // buggy : <=
+                                       THEN
     train_rear_end(tr) := train_rear_end(tr) + 1 ||
-    train_front_end(tr) := new_front ||
-    occ := {ttd | ttd:TTDS & TTD_TrackElements(ttd) /\ train_occ_all /= {}} /* buggy ; use seq. composition*/
+    train_front_end(tr) := new_front ;
+    occ := {ttd | ttd:TTDS & TTD_TrackElements(ttd) /\ train_occ_all /= {}} /* buggy ; use seq. composition instead of || */
   END
 DEFINITIONS
  "LibrarySVG.def"; // enable to use the external functions in the VisB json file
diff --git a/VisB-Examples.prob2project b/VisB-Examples.prob2project
index daa043b9cb905150544ccfcb2b0a3a62ee35c49f..4856c72980d37be8deea04143e4840088c3dd08f 100644
--- a/VisB-Examples.prob2project
+++ b/VisB-Examples.prob2project
@@ -422,17 +422,33 @@
       "symbolicAnimationFormulas": [],
       "simulationItems": [],
       "testCases": [],
-      "traces": [],
-      "modelcheckingItems": [],
+      "traces": [
+        "traces/TwoTrainsMA.prob2trace"
+      ],
+      "modelcheckingItems": [
+        {
+          "nodesLimit": "-",
+          "timeLimit": "-",
+          "options": {
+            "options": [
+              "FIND_DEADLOCKS",
+              "FIND_INVARIANT_VIOLATIONS",
+              "INSPECT_EXISTING_NODES"
+            ]
+          },
+          "goal": "-",
+          "shouldExecute": true
+        }
+      ],
       "simulation": null,
-      "visBVisualisation": null
+      "visBVisualisation": "Train/TwoTrainsMA.json"
     }
   ],
   "preferences": [],
   "metadata": {
     "fileType": "Project",
     "formatVersion": 12,
-    "savedAt": "2021-05-05T07:39:51.437871Z",
+    "savedAt": "2021-05-05T10:13:41.024463Z",
     "creator": "User",
     "proB2KernelVersion": "4.0.0-SNAPSHOT",
     "proBCliVersion": null,
diff --git a/traces/TwoTrainsMA.prob2trace b/traces/TwoTrainsMA.prob2trace
new file mode 100644
index 0000000000000000000000000000000000000000..17809f564c09f821204fb8efc90994d8fa83c67d
--- /dev/null
+++ b/traces/TwoTrainsMA.prob2trace
@@ -0,0 +1,651 @@
+{
+  "description": "",
+  "transitionList": [
+    {
+      "name": "$setup_constants",
+      "params": {},
+      "results": {},
+      "destState": {
+        "TTD_TrackElements": "{(ttd1↦{0,1,2,3,4}),(ttd2↦{5,6,7,8,9,10}),(ttd3↦{11,12,13,14,15,16,17,18,19,20,21,22,23,24,25}),(ttd4↦{26,27,28,29,30})}",
+        "TrackElementNumber": "30",
+        "TRACK": "{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30}"
+      },
+      "destStateNotChanged": [],
+      "preds": []
+    },
+    {
+      "name": "$initialise_machine",
+      "params": {},
+      "results": {},
+      "destState": {
+        "train_rear_end": "{(tr1↦0),(tr2↦5)}",
+        "train_front_end": "{(tr1↦2),(tr2↦6)}",
+        "train_ma": "∅",
+        "occ": "{ttd1,ttd2}"
+      },
+      "destStateNotChanged": [],
+      "preds": []
+    },
+    {
+      "name": "TrainAcceptsFirstMA",
+      "params": {
+        "newMA": "14",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_ma": "{(tr2↦14)}"
+      },
+      "destStateNotChanged": [
+        "train_front_end",
+        "train_rear_end",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "7",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦2),(tr2↦7)}",
+        "train_rear_end": "{(tr1↦0),(tr2↦6)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "8",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦2),(tr2↦8)}",
+        "train_rear_end": "{(tr1↦0),(tr2↦7)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainAcceptsFirstMA",
+      "params": {
+        "newMA": "4",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_ma": "{(tr1↦4),(tr2↦14)}"
+      },
+      "destStateNotChanged": [
+        "train_front_end",
+        "train_rear_end",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "9",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦2),(tr2↦9)}",
+        "train_rear_end": "{(tr1↦0),(tr2↦8)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "3",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦3),(tr2↦9)}",
+        "train_rear_end": "{(tr1↦1),(tr2↦8)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "10",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦3),(tr2↦10)}",
+        "train_rear_end": "{(tr1↦1),(tr2↦9)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "11",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_rear_end": "{(tr1↦1),(tr2↦10)}",
+        "train_front_end": "{(tr1↦3),(tr2↦11)}",
+        "occ": "{ttd1,ttd2,ttd3}"
+      },
+      "destStateNotChanged": [
+        "train_ma"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "12",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_rear_end": "{(tr1↦1),(tr2↦11)}",
+        "train_front_end": "{(tr1↦3),(tr2↦12)}",
+        "occ": "{ttd1,ttd3}"
+      },
+      "destStateNotChanged": [
+        "train_ma"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "13",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦3),(tr2↦13)}",
+        "train_rear_end": "{(tr1↦1),(tr2↦12)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainAcceptsNewMA",
+      "params": {
+        "newMA": "10",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_ma": "{(tr1↦10),(tr2↦14)}"
+      },
+      "destStateNotChanged": [
+        "train_front_end",
+        "train_rear_end",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "4",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦4),(tr2↦13)}",
+        "train_rear_end": "{(tr1↦2),(tr2↦12)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "5",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_rear_end": "{(tr1↦3),(tr2↦12)}",
+        "train_front_end": "{(tr1↦5),(tr2↦13)}",
+        "occ": "{ttd1,ttd2,ttd3}"
+      },
+      "destStateNotChanged": [
+        "train_ma"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainAcceptsNewMA",
+      "params": {
+        "newMA": "23",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_ma": "{(tr1↦10),(tr2↦23)}"
+      },
+      "destStateNotChanged": [
+        "train_front_end",
+        "train_rear_end",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "14",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦5),(tr2↦14)}",
+        "train_rear_end": "{(tr1↦3),(tr2↦13)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "6",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦6),(tr2↦14)}",
+        "train_rear_end": "{(tr1↦4),(tr2↦13)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "15",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦6),(tr2↦15)}",
+        "train_rear_end": "{(tr1↦4),(tr2↦14)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "7",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_rear_end": "{(tr1↦5),(tr2↦14)}",
+        "train_front_end": "{(tr1↦7),(tr2↦15)}",
+        "occ": "{ttd2,ttd3}"
+      },
+      "destStateNotChanged": [
+        "train_ma"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "16",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦7),(tr2↦16)}",
+        "train_rear_end": "{(tr1↦5),(tr2↦15)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "8",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦16)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦15)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "17",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦17)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦16)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "18",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦18)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦17)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainAcceptsNewMA",
+      "params": {
+        "newMA": "25",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_ma": "{(tr1↦10),(tr2↦25)}"
+      },
+      "destStateNotChanged": [
+        "train_front_end",
+        "train_rear_end",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "19",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦19)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦18)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "20",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦20)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦19)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "21",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦21)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦20)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "22",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦8),(tr2↦22)}",
+        "train_rear_end": "{(tr1↦6),(tr2↦21)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "9",
+        "tr": "tr1"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦9),(tr2↦22)}",
+        "train_rear_end": "{(tr1↦7),(tr2↦21)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "23",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦9),(tr2↦23)}",
+        "train_rear_end": "{(tr1↦7),(tr2↦22)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    },
+    {
+      "name": "TrainMoveForward",
+      "params": {
+        "new_front": "24",
+        "tr": "tr2"
+      },
+      "results": {},
+      "destState": {
+        "train_front_end": "{(tr1↦9),(tr2↦24)}",
+        "train_rear_end": "{(tr1↦7),(tr2↦23)}"
+      },
+      "destStateNotChanged": [
+        "train_ma",
+        "occ"
+      ],
+      "preds": []
+    }
+  ],
+  "variableNames": [
+    "occ",
+    "train_rear_end",
+    "train_front_end",
+    "train_ma"
+  ],
+  "constantNames": [
+    "TrackElementNumber",
+    "TRACK",
+    "TTD_TrackElements"
+  ],
+  "setNames": [
+    "TTDS",
+    "TRAINS"
+  ],
+  "machineOperationInfos": {
+    "TrainMoveForward": {
+      "operationName": "TrainMoveForward",
+      "parameterNames": [
+        "tr",
+        "new_front"
+      ],
+      "outputParameterNames": [],
+      "topLevel": true,
+      "type": "CLASSICAL_B",
+      "readVariables": [
+        "TRACK",
+        "TTD_TrackElements",
+        "train_front_end",
+        "train_ma",
+        "train_rear_end"
+      ],
+      "writtenVariables": [
+        "occ",
+        "train_front_end",
+        "train_rear_end"
+      ],
+      "nonDetWrittenVariables": [],
+      "typeMap": {
+        "'TTD_TrackElements'": "set(couple(global('TTDS'),set(integer)))",
+        "new_front": "integer",
+        "tr": "global('TRAINS')",
+        "'TRACK'": "set(integer)"
+      }
+    },
+    "TrainAcceptsFirstMA": {
+      "operationName": "TrainAcceptsFirstMA",
+      "parameterNames": [
+        "tr",
+        "newMA"
+      ],
+      "outputParameterNames": [],
+      "topLevel": true,
+      "type": "CLASSICAL_B",
+      "readVariables": [
+        "TRACK",
+        "train_front_end",
+        "train_ma",
+        "train_rear_end"
+      ],
+      "writtenVariables": [
+        "train_ma"
+      ],
+      "nonDetWrittenVariables": [],
+      "typeMap": {
+        "newMA": "integer",
+        "tr": "global('TRAINS')",
+        "'TRACK'": "set(integer)"
+      }
+    },
+    "TrainAcceptsNewMA": {
+      "operationName": "TrainAcceptsNewMA",
+      "parameterNames": [
+        "tr",
+        "newMA"
+      ],
+      "outputParameterNames": [],
+      "topLevel": true,
+      "type": "CLASSICAL_B",
+      "readVariables": [
+        "TRACK",
+        "train_front_end",
+        "train_ma",
+        "train_rear_end"
+      ],
+      "writtenVariables": [
+        "train_ma"
+      ],
+      "nonDetWrittenVariables": [],
+      "typeMap": {
+        "newMA": "integer",
+        "tr": "global('TRAINS')",
+        "'TRACK'": "set(integer)"
+      }
+    }
+  },
+  "globalIdentifierTypes": {
+    "train_ma": "set(couple(global('TRAINS'),integer))",
+    "train_front_end": "set(couple(global('TRAINS'),integer))",
+    "train_rear_end": "set(couple(global('TRAINS'),integer))",
+    "occ": "set(global('TTDS'))"
+  },
+  "metadata": {
+    "fileType": "Trace",
+    "formatVersion": 2,
+    "savedAt": "2021-05-05T08:42:50.789906Z",
+    "creator": "traceReplay",
+    "proB2KernelVersion": "4.0.0-SNAPSHOT",
+    "proBCliVersion": "1.11.0-nightly",
+    "modelName": "TwoTrainsMA"
+  }
+}
\ No newline at end of file