If the closed stream is the current input, output or error stream, the stream alias is bound to the initial standard I/O streams of the process. Calling close/1 on the initial standard I/O streams of the process is a no-op for an input stream and flushes an output stream without closing it.^{91This behaviour was defined with purely interactive usage of Prolog in mind. Applications should not count on this behaviour. Future versions may allow for closing the initial standard I/O streams.}