V8+ were not publicly available, so the successors to V7 were 4BSD and System V. Hence repurposing Hoare, V7 “was not only an improvement on its predecessors, b

V8+ were not publicly available, so the successors to V7 were 4BSD and System V. Hence repurposing Hoare, V7 “was not only an improvement on its predecessors, but also on nearly all its successors”.