Life with Unix says: Wrote dc and be with Lorinda Cherry.

A Research Unix Reader says: Bob (Robert) Morris stepped in wherever mathematics was involved, whether it was numerical analysis or number theory. Bob invented the distinctively original utilities typo, and dc-bc (with Lorinda Cherry), wrote most of the math library, and wrote primes and factor (with Thompson). His series of crypt programs fostered the Center's continuing interest in cryptography.