nearly there

mCRL2/TrafficLights/v4/v4_spec.mcrl2

@@ -47,27 +47,30 @@ proc
 	TrafficLight(direction : CardinalDirection) = TL(direction, red, true);
 
 	TL(direction : CardinalDirection, colour : Colour, firstStart : Bool) =
-		(firstStart)
-		-> changeDirection(direction) . ChangeLight(direction, colour)
-		<>
-			show(direction, colour) .
-			(colour == red) 
-				-> ChangeDirection(direction) . ChangeLight(direction, colour)
-				<> ChangeLight(direction, colour)
+		(firstStart) %beim ersten Start nur das Licht umschalten
+		-> changeDirection(direction) . TL(direction, colour, false)
+		<> %ansonsten
+			show(direction, colour) . %aktuellen Zustand zeigen
+			(colour == red) %wenn rot
+				-> ChangeDirection(direction) %Richtungswechsel, wenn wieder zurück
+					. ChangeLight(direction, colour) % -> zur nächsten Farbe wechseln.
+				<> ChangeLight(direction, colour) %ansonsten zum nächsten Zustand wechseln.
 		
 	;
 
 	ChangeDirection(direction : CardinalDirection) =
-		changeDirection(nextDirection(direction)) . changeDirection(direction)
+		changeDirection(nextDirection(direction)) %nächste Richtung freigeben 
+		. changeDirection(direction) % -> warten bis eigene Richtung wieder freigegeben.
 	;
 	
 	ChangeLight(direction : CardinalDirection, colour : Colour) =
-		changeLight(nextColour(colour)) . TL(direction, nextColour(colour), false)
+		changeLight(nextColour(colour)) %zur nächsten Farbe wechseln, wenn beide Richtungen dies autorisieren
+		. TL(direction, nextColour(colour), false) %fortfahren
 	;
 
 	System =
 		allow({
-			show, 
+			show,
 			%changeLight,
 			changedLight,
 			%changeDirection, 
@@ -77,10 +80,10 @@ proc
 		comm({
 			changeDirection | changeDirection -> changedDirection,
 			changeLight | changeLight -> changedLight
-			
 		},
 
 		TrafficLight(north) || TrafficLight(east) || TrafficLight(south) || TrafficLight(west) || changeDirection(north) || changeDirection(south)
+		%starten der Prozesse und auslösen des ersten Richtungswechsels
 	));
 
 init