 Let us denote by \(B = \{h_{1}, \ldots ,h_{n}\}\) a set of mutually exclusive and jointly exhaustive hypotheses. Here the hypotheses in \(B\) may be the most informative descriptions of alternative states of affairs or possible worlds within a conceptual framework \(L\). For example, they may be complete theories expressible in a finite first-order language. If \(L\) is interpreted on a domain \(U\), so that each sentence of \(L\) has a truth value (true or false), it follows that there is one and only one true hypothesis (say \(h^*\)) in \(B\). Our cognitive problem is to identify the target \(h^*\) in \(B\). The elements \(h_{i}\) of \(B\) are the (potential) complete answers to the problem. The set \(D(B)\) of partial answers consists of all non-empty disjunctions of complete answers. The trivial partial answer in \(D(B)\), corresponding to ‘I don’t know’, is represented by a tautology, i.e., the disjunction of all complete answers. 