anchor.diff:  % several maps, the value in the first nested map is superseded by the value in
   % a following nested map.
   %
  -% The call fails with a `{badmap,Map}' exception if `Map1' or `Map2' is not a
  -% map.
  +% The call can raise the following exceptions:
  +% <ul>
  +% <li>`{badmap,Map}' exception if any of the maps is not a map</li>
  +% </ul>
   %
   % @equiv deep_merge(fun (_, V) -> V end, #{}, Maps)
   -spec deep_merge([map()]) -> map().
  
positive.code: % @doc Returns a tuple `{ok,Value}', where Value is the value associated with
  % `Path', or `error' if no value is associated with `Path' in `Map'.
  %
  % The call fails with a `{badmap,Map}' exception if `Map' is not a map, or with
  % a `{badpath,Path}' exception if `Path' is not a path.
  -spec deep_find(path(), map()) -> {ok, term()} | error.
  deep_find(Path, Map) ->
      check(Path, Map),
  
negative.code: %
  % The call can raise the following exceptions:
  % <ul>
  % <li>`{badmap,Map}' if `Map' is not a map</li>
  % <li>`{badpath,Path}' if `Path' is not a path</li>
  % <li>`{badvalue,P}' if a term that is not a map exists as a intermediate key at
  %     the path `P'</li>
  