anchor.diff:  
   abs_environment_closure_negative_test_() ->
     {foreachx,
  -   fun
  -     ([{mock_tpar,false}]) ->              setup();
  -     ([{mock_tpar, true}]) -> mock_tpar(), setup()
  +   fun(Options) ->
  +       case proplists:get_bool(mock_tpar, Options) of
  +         true  -> mock_tpar();
  +         false -> nothing
  +       end,
  +       setup()
      end,
  -   fun
  -     ([{mock_tpar,false}], Pid) -> cleanup(Pid);
  -     ([{mock_tpar, true}], Pid) -> cleanup(Pid), unmock_tpar()
  +   fun(Options, Pid) ->
  +       cleanup(Pid),
  +       case proplists:get_bool(mock_tpar, Options) of
  +         true  -> unmock_tpar();
  +         false -> nothing
  +       end
      end,
      lists:append(
        [
  
positive.code: 
  %% Internals
  
  compose_tree_and_b_abs(ASTGenFun, {mock_tpar, FAbs}) ->
    {{mock_tpar, true}, ASTGenFun(FAbs)};
  compose_tree_and_b_abs(ASTGenFun, FAbs) ->
    {{mock_tpar,false}, ASTGenFun(FAbs)}.
  
  ensure_option_in_test(TestGenFun, {{mock_tpar,_Bool}=MockTParOpt, SOrT}) ->
    F = fun(_,_) -> %% Fun needed for usage of foreachx
            TestGenFun(SOrT)
        end,
    {[MockTParOpt], F};
  ensure_option_in_test(TestGenFun, SOrT) ->
    ensure_option_in_test(TestGenFun, {{mock_tpar,false}, SOrT}).
  
  
  mock_tpar() ->
  
negative.code:    {'@', s("#.t"), {t, [{{dim,"t"}, BAbs}]}},
     %% "#.t @ [t <- \_x -> A]"
     %%
     {[mock_tpar],
      {'@', {b_abs, [], [s("x")], 1}, %% A harmless b_abs, just for returning one
       {t, [
            %% Define a tuple with a dummy dimension idetifier-ordinate
  