$ sudo apt-get remove libfann-dbg 

Uninstall libfann-dbg including dependent package

If you would like to remove libfann-dbg and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libfann-dbg 

Use Purging libfann-dbg

If you use with purge options to libfann-dbg package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libfann-dbg 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove libfann-dbg 

See Also,