Used to test whether Term is a handle. Handles are references to anonymous ECLiPSe objects (such as streams, engines, bags, records, shelves, stores) or to external data created via the foreign language interfaces.
?- bag_create(B), is_handle(B).
B = $&(bag,"371bnb")
Yes (0.00s cpu)
?- is_handle(_).
No (0.00s cpu)
?- is_handle(42).
No (0.00s cpu)