/usr/share/man/man1/lxdm-greeter-gdk.1.gz is in lxdm 0.5.3-2.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/lxdm.1.gz
/usr/share/man/man1/lxdm.1.gz