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coroutine
Switches on the coroutine flag, equivalent to set_flag(coroutine, on).
This built-in predicate is obsolete!
Description
Used to switch the global coroutine-flag to on. This causes a subset of
the built-in predicates not to raise instantiation faults any longer but
to delay instead. This concerns all sufficiently logical predicates
like the arithmetic built-ins, functor/3, arg/3, and many others.
Modes and Determinism
Examples
[eclipse 1]: X>0.
instantiation fault in X > 0
[eclipse 2]: coroutine.
yes.
[eclipse 3]: X>0.
X = X
Delayed goals:
X > 0
yes.
See Also
set_flag / 2