 That is, \(\beta(A)\) is the difference between the minimal rank of the \(\neg A\)-worlds and the minimal rank of the \(A\)-worlds. For example, if \(\kappa(\neg A)\) is rather high, we strongly believe \(A\). \(\beta(A)&gt;0\) means that \(A\) is believed to be true, and \(\beta(A)&lt;0\) that \(A\) is believed to be false. \(\beta(A)=0\) means that \(A\) is neither believed nor disbelieved. In the latter case, we have both \(A\)- and \(\neg A\)-worlds whose rank is zero.