How to implement a "switch" in a rule set?
Declare a variable called "done".


First rule in the set checks for role A, sets done and redirects. 
Second rule in the set checks if done is true, and role is B, sets done and
redirects. 
Third rule in the set checks if done is true, and role is
C, sets done and redirects. 
Fourth rule checks if done is true,
redirects.