outputs the newline-character.
nl/0 outputs the newline-character at the current outputstream.
nl/1 outputs the newline-character at the stream named in the first argument (Stream).
Stream text output stream
Assume the content of a stream S is abcdefg and the stream position is behind the last character.
| nl(S). | Succeeds. The current inputstream is now | abcdefg\n |
These predicates are part of the ISO-Prolog Standard.