simplified selection string (avoid creating empty rules)
simplified selection string (avoid creating empty rules)

TODO filter out empty rules in Selection class

arose/ngl,fredludlow/ngl,fredludlow/ngl,j0kaso/ngl,arose/ngl,j0kaso/ngl,fredludlow/ngl,arose/ngl,arose/ngl,j0kaso/ngl,fredludlow/ngl