We prove that there is no preferential voting method satisfying the Condorcet winner and loser criteria, positive involvement (if a candidate $x$ wins in an initial preference profile, then adding a voter who ranks $x$ uniquely first cannot cause $x$ to lose), and resolvability (if $x$ initially ties for winning, then $x$ can be made the unique winner by adding a single voter). In a previous note, we proved an analogous result assuming an additional axiom of ordinal margin invariance, which we now show is unnecessary for an impossibility theorem, at least if the desired voting method is defined for five-candidate elections.

翻译：我们证明不存在满足孔多塞胜者与败者准则、积极介入性（若候选人$x$在初始偏好剖面中获胜，则增加一位将$x$唯一排在首位的投票者不会导致$x$落败）及可解性（若$x$最初与其他候选人并列获胜，则可通过增加一位投票者使$x$成为唯一胜者）的优先投票方法。在先前的笔记中，我们在假设序数边际不变性这一附加公理的前提下证明了类似结论，而本文表明该公理对于不可能性定理并非必要——至少在所求投票方法需适用于五候选人选举时成立。