# File lib/ruote/exp/ro_attributes.rb, line 189
    def lval(vals, vars, flds, att_options)

      if k = has_att(*vals)

        attribute(k, h.applied_workitem, att_options)

      elsif k = has_att(*vars)

        k = attribute(k, h.applied_workitem, att_options)
        lookup_variable(k)

      elsif k = has_att(*flds)

        k = attribute(k, h.applied_workitem, att_options)
        Ruote.lookup(h.applied_workitem['fields'], k)

      else

        nil
      end
    end