On Tue, Sep 18, 2018 at 04:58:52PM +0000, znavko wrote:
> Here are presented only xfce-desktop-service, gnome-desktop-service, mate-desktop-service, but no lxde.

These services, which provide desktop using XFCE, GNOME, and MATE, are
defined in the file 'gnu/services/desktop.scm':

https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/services/desktop.scm

Currently, we don't have a desktop service for LXDE.

Maybe a service is not required? It's possible to use i3 without a
desktop service. One just adds 'i3-wm' to the 'packages' field of their
config.scm and it will be available at the login screen.

>   ;; This is where we specify system-wide packages.
>   (packages (cons* nss-certs         ;for HTTPS access
>                    gvfs              ;for user mounts
>                    gedit
>                    icecat
>                    %base-packages))

You could try adding lxde to that list...

> 
>   ;; Add GNOME and/or Xfce---we can choose at the log-in
>   ;; screen with F1.  Use the "desktop" services, which
>   ;; include the X11 log-in service, networking with
>   ;; NetworkManager, and more.
>   (services (cons* (xfce-desktop-service)
>                    %desktop-services))

... and, unless you want to use XFCE, change that to (services
%desktop-services)