This is where I collect and write things, mostly on academe and artificial intelligence. Established in 2010, by Vaishak Belle.
I have seen a lot of confusion about ground truth vs what the system knows, and why we even need to distinguish the two.
The above example, from the logic of knowledge bases (MIT press) textbook, is particularly illustrative. We could use a formula of the form
Using both first order atoms and modal atoms to capture just that, and without both, it just wouldn’t work.