Recommends: xkb-data, x-terminal-emulator, pavucontrol | gnome-alsamixerWhat is meaning for here the x-terminal-emulator?I find one link,but what should installed?Is this undefined behavior?For exmaple:root@debian:/# cat /etc/os-release |grep ^PRETTY_NAMEPRETTY_NAME=Debian GNU/Linux 9 (stretch)root@debian:/# aptitude --disable-columns show lxpanelPackage: lxpanel                         Version: 0.9.3-1State: not installedPriority: optionalSection: x11Maintainer: Debian LXDE Maintainers <pkg-lxde-maintainers@lists.alioth.debian.org>Architecture: i386Uncompressed Size: 753 kDepends: libasound2 (>= 1.0.16), libatk1.0-0 (>= 1.12.4), libc6 (>= 2.7), libcairo2 (>= 1.2.4), libfm-gtk4 (>= 1.2.0), libfm4 (>= 1.2.0), libfontconfig1 (>= 2.11), libfreetype6         (>= 2.2.1), libgdk-pixbuf2.0-0 (>= 2.22.0), libglib2.0-0 (>= 2.41.1), libgtk2.0-0 (>= 2.24.0), libiw30 (>= 30~pre1), libkeybinder0 (>= 0.3.0), libmenu-cache3 (>= 0.5.0),         libpango-1.0-0 (>= 1.14.0), libpangocairo-1.0-0 (>= 1.14.0), libpangoft2-1.0-0 (>= 1.14.0), libwnck22 (>= 2.30.7), libx11-6, libxml2 (>= 2.7.4), lxmenu-data, lxpanel-data         (= 0.9.3-1), libfm-modulesRecommends: xkb-data, x-terminal-emulator, pavucontrol | gnome-alsamixerSuggests: menu, firefox-esr | firefox | www-browserDescription: LXDE panel LXPanel is a GUI application for the Lightweight X11 Desktop Environment (LXDE).  It is derived from fbpanel and includes the following features:  * User-friendly application menu automatically generated from .desktop files on the system  * Launcher bar (small icons clicked to launch apps)  * Task bar supporting ICCCM/EWMH `urgency' hint (Pidgin IM windows can flash on new incoming messages)  * Run dialog (type a command to run, without opening a terminal)  * Net status icon plug-in (optional).  * Volume control plug-in (optional).  * Notification area (system tray).  * Digital clock.  * Keyboard LEDs plug-in (display caps/num locks).  * lxpanelctl: control lxpanel from other programs. For example, lxpanelctl run will show the Run dialog in lxpanel, and lxpanelctl menu will show the application menu. This   is useful in combination with window manager key bindings.Homepage: http://www.lxde.org/Tags: hardware::input:mouse, interface::graphical, interface::x11, role::program, scope::utility, suite::TODO, uitoolkit::gtk, use::TODO, works-with::software:package,      works-with::software:running, x11::applet, x11::applicationroot@debian:/# Below-is-old-contents(found answer)Why prompt me termit will installed,Why is not lxterminal will installed?I expect lxerminal will installed because lxde-core first recommend lxterminal ,but why is termit will installed?What I did and encountered:If you need any more information can tell me ,thankroot@debian:~/debian_stretch# debootstrap stretch ./ http://ftp.cn.debian.org/debian/ >/dev/nullroot@debian:~/debian_stretch# mount --bind /sys ./sysroot@debian:~/debian_stretch# mount --bind /proc ./procroot@debian:~/debian_stretch# chroot ./root@debian:/# apt update >/dev/null 2>&1root@debian:/# echo Y |apt upgrade >/dev/null 2>&1root@debian:/# echo n |apt install lxde-core 2>&1| grep -o termittermittermitroot@debian:/# echo n |apt install lxde-core 2>&1| grep -o lxterminalroot@debian:/# echo n |apt-get install lxde-core 2>&1| grep -o termittermittermitroot@debian:/# echo n |apt-get install lxde-core 2>&1| grep -o lxterminalroot@debian:/# apt-cache policy termittermit:  Installed: (none)  Candidate: 3.0-1+b1  Version table:     3.0-1+b1 500        500 http://ftp.cn.debian.org/debian stretch/main i386 Packagesroot@debian:/# apt-cache policy lxterminallxterminal:  Installed: (none)  Candidate: 0.3.0-2  Version table:     0.3.0-2 500        500 http://ftp.cn.debian.org/debian stretch/main i386 Packagesroot@debian:/#Again,if you need any more information can tell me ,thank
What is happen when virtual package depends/recommeds/suggest without real package depends/recommeds/suggest?
debian;apt;dpkg;lxde;aptitude