$ sudo apt-get update
$ sudo apt-get install libpgraphutil-smlnj 

libpgraphutil-smlnj is installed in your system.

Make ensure the libpgraphutil-smlnj package were installed using the commands given below,

$ sudo dpkg-query -l | grep libpgraphutil-smlnj *

You will get with libpgraphutil-smlnj package name, version, architecture and description in a table

libpgraphutil-smlnj package basic information: