Taking a wild guess, but I would figure it's about distinguishing statements about truth values and statements about sets. If you think of it as a function, ta

Taking a wild guess, but I would figure it's about distinguishing statements about truth values and statements about sets. If you think of it as a function, takes in two booleans and returns a booleen. Likewise ⊂ takes a thing and a set and returns a booleen. I've never really been a fan of ⊃, and always personally preferred an arrow.