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 $n$-voter resolvability (if $x$ initially ties for winning, then $x$ can be made the unique winner by adding some set of up to $n$ voters). This impossibility theorem holds for any positive integer $n$. It also holds if either the Condorcet loser criterion is replaced by independence of clones or positive involvement is replaced by negative involvement.

翻译：我们证明不存在满足孔多塞胜者准则与败者准则、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）以及$n$投票者可解性（若$x$初始与其他候选人并列获胜，则可通过增加不超过$n$位投票者使$x$成为唯一胜者）的优先投票方法。该不可能性定理对任意正整数$n$均成立。若将孔多塞败者准则替换为克隆独立性，或将积极介入性替换为消极介入性，该定理依然成立。