progn: Symbol’s function definition is void: f-symlink

[Hongyi Zhao]

I use the following code in my `.emacs.d/init.el` to install the qe-modes [1]:

;;;;;;; begin ;;;;;;;
(let ((qe-modes-source "~/.emacs.d/qe-modes")
      (qe-modes-symlink "~/Public/hpc/QEF/q-e.git/GUI/QE-modes/qe-modes")
      (qe-modes-emacs "~/Public/hpc/QEF/q-e.git/GUI/QE-modes/qe-modes.emacs"))

  (when (not (file-directory-p (file-truename qe-modes-source)))
    (when (file-symlink-p qe-modes-source)
      (delete-file qe-modes-source))
    (f-symlink (file-truename qe-modes-symlink) qe-modes-source))

  (load-file qe-modes-emacs))
;;;;;;; end ;;;;;;;


All the files required for the above code exist on my computer:

werner@X10DAi-00:~$ ls ~/Public/hpc/QEF/q-e.git/GUI/QE-modes/qe-modes
cp-mode.el    neb-mode.el   pp-mode.el   pwtk-mode.el   qe-mode.el
cp-mode.elc   neb-mode.elc  pp-mode.elc  pwtk-mode.elc  qe-mode.elc
ld1-mode.el   ph-mode.el    pw-mode.el   qe-funcs.el    qe-modes.el
ld1-mode.elc  ph-mode.elc   pw-mode.elc  qe-funcs.elc   qe-modes.elc
werner@X10DAi-00:~$ ls ~/Public/hpc/QEF/q-e.git/GUI/QE-modes/qe-modes.emacs
/home/werner/Public/hpc/QEF/q-e.git/GUI/QE-modes/qe-modes.emacs


But when I start Emacs, the following error is triggered:

progn: Symbol’s function definition is void: f-symlink

Any hints for fixing this problem?

[1] http://pwtk.ijs.si/qe-modes.html

Regards
HZ