Robert said after 6.1 was released that multiple copies were allowed (upto 4 per license) as long as only one copy was used at a time. So for example, I am the only one that uses my Hal but I have it on two computers. I never have both copies running at the same time but share my brain files between Hals. If someone else in my household used Hal, I would need to buy another license.
I did a search for 'License' then looked under the subject 'Hal assistant 6.1 WORK'
Hope this clarifies.