$ sudo apt-get update
$ sudo apt-get install libgnu-regexp-java 

libgnu-regexp-java is installed in your system.

Make ensure the libgnu-regexp-java package were installed using the commands given below,

$ sudo dpkg-query -l | grep libgnu-regexp-java *

You will get with libgnu-regexp-java package name, version, architecture and description in a table

libgnu-regexp-java package basic information: