  We study a class of elections in which the input format is trichotomous and
allows voters to elicit their negative feelings explicitly. In particular, we
study multiwinner elections with a special proclivity to elect proportionally
representative committees. That is, we design various axioms to deal with
negative feelings and suggest some structures to these preferences that allow
better preference aggregation rules. We propose two different classes of axioms
designed to aggregate trichotomous preferences more efficiently. We propose
trichotomous versions of some well known multiwinner voting rules and report
their satisfiability of our axioms. Hence, with reports of our simulations as
evidence, we build upon the social optimality of our proportionality based
axioms to evaluate the quality of voting rules for electing a proportionally
representative committee with trichotomous ballots as inputs.
