I want to model a logic of beliefs with two agents where :
$$M,w^*⊨\phi\wedge Ba\phi\wedge Bb\neg\phi\wedge BaBb\neg\phi$$
I think I'm using Kripke semantics.
I think that i.e. it describe a world where it exists $\phi$, $a$ beleives it, $b$ don't believe it and $a$ believes $b$ don't believe it.
I thought about :
Even if I wasn't sure about the arrow of $a$ on $\phi$ and $b$ on $\neg\phi$. Yet it didn't displayed the fact that $a$ believes that $b$ don't believe $\Phi$.
The answer the teacher gave was :
I understand that the $w^*$ shows that the actual world is on the left side but on the right side I don't understand this part as far as, to my mind, it shows that b believes $\neg\phi$ as well which is wrong in logic of belief.