These observations lead to the following channel matrix, to 4 decimal places:
          | AAD    | ADA    | DAA    | DDD    
 user1    | 0.1875 | 0.1875 | 0.4375 | 0.1875 
 user2    | 0.1875 | 0.4375 | 0.1875 | 0.1875 
 user3    | 0.4375 | 0.1875 | 0.1875 | 0.1875 


Mutual information: 0.1038   Calculated with the uniform input distribution.
The attacker learns 0.1038 bits, out of a possible  1.585 bits, about the input events.
