# File lib_core/rucy/document.rb, line 311
    def set_alias(alias_path, orig_path)
      if (alias_path !~ %"^/") then
        raise "not a path: #{alias_path.inspect}"
      end
      if (orig_path !~ %"^/") then
        raise "not a path: #{orig_path.inspect}"
      end
      @alias_map[alias_path] = orig_path
      nil
    end