By virtue of the Kemeny distance strategy-proofness of preference rules is defined. It is shown that a preference rule, which assigns a complete relation to every profile of complete relations is non-imposed and strategy-proof if and only if it is pairwise voting in committees. So, non-imposedness and strategy-proofness together imply the independence of irrelevant alternatives condition. Furthermore, it is shown that in this setting pairwise voting in committees coincides with coordinatewise veto voting. Taking acyclic preference rules into consideration, which assign an acyclic complete relation to every profile of acyclic complete relations, it follows that under strategy-proofness and non-imposition the independence of irrelevant alternatives is equivalent to indifference monotonicity. Now it follows that an acyclic preference rule is non-imposed, strategy-proof and indifference monotonic if and only if it is coordinatewise veto voting with respect to a cycle free assignment of disagreements.
