anchor.diff:  %% X gets a new, local binding.
   %% (Note that lowercase 'let' is a reserved word.)
   -ifndef(LET).
  --define(LET(X,Y,Z), ((fun(X)->(Z)end)(Y))).
  +-define(LET(X,Y,Z), begin ((fun(X)->(Z)end)(Y)) end).
   -endif.
   
   %% It is important that testing code is short and readable.
  
positive.code: 			_ -> ok
  		    end
  	    end
  	  end)())).
  -endif.
  -define(_assertNotException(Class, Term, Expr),
  	?_test(?assertNotException(Class, Term, Expr))).
  
negative.code: -define(assertMatch(Guard, Expr), ok).
  -else.
  -define(assertMatch(Guard, Expr),
  	begin
  	((fun () ->
  	    case (Expr) of
  		Guard -> ok;
  