This replaces the most usages of MonadPlus, which is not appropriate for the resolvers, since a resolver is unambiguously chosen by the name (no need for 'mplus'), and the resolvers are often doing IO.
This replaces the most usages of MonadPlus, which is not appropriate for the resolvers, since a resolver is unambiguously chosen by the name (no need for 'mplus'), and the resolvers are often doing IO.