title: Eiffel: unknown identifier `cursor` on LINKED_LIST[STRING]
body: <p>I have an <code>unknown identifier</code> on the local <code>like some_values.cursor</code>, I really don't understand why!</p>
  
  <pre><code>qry_update_set_fields (some_keys, some_values, some_unstored_field_names: LINKED_LIST[STRING]): STRING
      require
          same_some_keys_some_values_count: some_keys.count = some_values.count
      local
          l_val_c: like some_values.new_cursor
      do
          Result := ""
          l_val_c := some_values.new_cursor
          across
              some_keys as l_key_c
          loop
              Result := l_key_c.item + "=" + l_val_c.item + ","
              l_val_c.forth
          end
          if Result.ends_with (",") then
              Result.remove_tail (1)
          end
      ensure
          dont_modify_parameters: old some_keys.is_equal (some_keys) and old some_values.is_equal (some_values)
      end
  </code></pre>
  
  <h2>working</h2>
  
  <pre><code>l_val_c: LINKED_LIST_CURSOR [STRING]
  </code></pre>
  
  <h2>Neither working</h2>
  
  <pre><code>l_val_c: LINKED_LIST_CURSOR [like some_values.item]
  </code></pre>