 With relatively few exceptions, the logical approaches to defeasible reasoning developed so far put severe restrictions on the logical form of propositions included in a set of premises. In particular, they require the default conditional operator, \(\Rightarrow\), to have wide scope in every formula in which it appears. Default conditionals are not allowed to be nested within other default conditionals, or within the scope of the usual Boolean operators of propositional logic (negation, conjunction, disjunction, material conditional). This is a very severe restriction and one that is quite difficult to defend. For example, in representing undercutting defeaters, it would be very natural to use a negated default conditional of the form \(\neg((p \amp q) \Rightarrow r)\) to signify that \(q\) defeats \(p\) as a prima facie reason for \(r\). In addition, it seems plausible that one might come gain disjunctive default information: for example, that either customers are gullible or salesman are wily.