```common lisp
;;;;; tré – Copyright (c) 2013 Sven Michael Klose <pixel@copei.de>

(defvar *terpri* (format nil "~%"))
```

Use CODE-CHAR instead of FORMAT.
user
```common lisp
;;;;; tré – Copyright (c) 2013–2014 Sven Michael Klose <pixel@copei.de>

(defvar *terpri* (string (code-char 10)))
```
assistant