anchor.diff:  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   %%% 
   
  --type product_offering_status() :: in_study | in_design | in_test
  +-type offer_status() :: in_study | in_design | in_test
   		| active | rejected | launched | retired | obsolete.
   -type product_status() :: created | pending_active | aborted
   		| cancelled | active | suspended | pending_terminate | terminated.
  
positive.code: 		start_date :: '_' | pos_integer() | undefined,
  		end_date :: '_' | pos_integer() | undefined,
  		is_bundle = false :: '_' | boolean() | undefined,
  		status :: product_offering_status() | '_' | undefined,
  		specification :: string(),
  		price :: '_' | [#price{}],
  		characteristics = [] :: [tuple()],
  
negative.code: 		{product :: string(),
  		start_date :: pos_integer(),
  		termination_date :: pos_integer(),
  		status :: product_status(),
  		characteristics = [] :: [tuple()],
  		last_modified :: tuple() | '_' | undefined}).
  
  