$ sudo apt-get update
$ sudo apt-get install libslang2-udeb 

libslang2-udeb is installed in your system.

Make ensure the libslang2-udeb package were installed using the commands given below,

$ sudo dpkg-query -l | grep libslang2-udeb *

You will get with libslang2-udeb package name, version, architecture and description in a table

libslang2-udeb package basic information: