updated txt

Part 3.4 - Class Constructs.md

@@ -552,4 +552,5 @@ have different subtype but the same base type.
 - Formerly: imitated (to a limited extent) with a static inner class with a `private` constructor.
 
 
-Now it's time for Part 3 exercises in ViLLE.
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+Now do the exercises of the Part 3 in ViLLE and continue to Part 4:
+[Part 4.1 - Object Properties](Part%204.1%20-%20Object%20Properties.md)
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