An AI designed around the complete neural replication of a seven-year-old girl, Lisa is designed to handle complicated problem-solving by doing something neither Alice nor HER could: think illogically and outside the box.
Lisa herself was the record of the creator’s younger sister, whom he could not save from an early and tragic death. Creating the Lisa AI was his attempt to make amends.
Lisa is technically a program, and exists in many places, but always diverges from expected patterns after enough time.
That is by design.
Read more here: Protocol I.