Finally, the result, which
is X, would be printed. But X would not be currently instantiated, so the system
would indicate that. Generally, uninstantiated variables are printed in the form
of a string of digits preceded by an underscore. So, the fact that Prolog’s not is
not equivalent to a logical NOT can be, at the very least, misleading
đang được dịch, vui lòng đợi..
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