uml/state-machine-diagram.md

@@ -61,6 +61,14 @@ The execution of the state machine level is finished, if a *final state* on the
 One level of hierarchy (e.g. *region*) may contain any number of *terminate pseudostates*.
 The overall execution of the state machine is discontinued, if one *terminate pseudostates* at any level is reached.
 
+- *Choice pseudostates* a denoted as diamond-shaped symbols.
+*Choice pseudostates* may have multiple (at least two) outgoing *transitions*.
+"If a *choice pseudostate* is reached with multiple outgoing *transitions* with *guards*, a *transition* whose *guard* evaluates to true will be taken.
+If more than one *guard* evaluates to true, one of these *transitions* is chosen for continuing the
+traversal.
+The algorithm for making this selection is undefined.
+If no guards evaluate to true when the *choice pseudostate* is reached, the model is ill formed" and requires rework.
+
 # Obligations for the lectures and the final exam in "Softwaretechnik" (Tips for Modeling)
 When creating a **state machine diagram**, remember that it must contain all necessary information (e.g. states, transitions, triggers, guards and effects).
 Especially for transitions between states it is important to specify the relevant triggers, guards, and behaviors.