A, B, and C are the 3 possible perspectives a subject possesses regarding a t/f proposition.
A proposition is either true or false.
Perspectives:
Subject A: "I have concluded that the proposition is true!"
Subject B: "I have concluded that the proposition is false!"
Subject C: "I have not concluded whether or not the proposition is true or false!!!!"
Now let's say the proposition is true. Thus, A would be correct, and B would be incorrect.
Now let's sat the proposition is false. Thus, A would be incorrect, and B would be correct.
I could see this work. I think it is slightly to what I explained a little more detailed.
The idea of X and Y is where the objectivity begins and subjectivity ends. I would assume. Every subject (A, B, C) are suppose to compare their proposition to X and Y inorder to achieve the correct path whatever it may be.