Slim - negative argument

gistfile1.txt

== yield
  - if page.meta.includes_editions
    - page.meta.includes_editions.split(',').map{ |id| index["plugins/editions/#{id.strip}"] }.to_a.sort_by {|i| i.meta.sort_field}.each do |e|
      - if e
        h3 Also includes plugins from the 
          a href="#{e.path}" 
            = e.heading
        - e.edition_plugins.each do |plugin|
          li
            a(href="#{plugin.path}")= plugin.heading
            |  - 
            = plugin.meta.tagline