Availability:built-in
[det]engine_yield(+Term)Called from within the engine, causing engine_next/2
in the caller to return with Term. A subsequent call to engine_next/2
causes
engine_yield/1
to `return'. This predicate can only be called if the engine is not
involved in a callback from C, i.e., when the engine calls a predicate
defined in C that calls back Prolog it is not possible to use this
predicate. Trying to do so results in a
permission_error exception.