Where “simulation” came from

When did computer scientists start to talk about “simulation” between programs? As of a couple of months ago, the earliest paper I had seen on this topic was Robin Milner’s widely cited IJCAI 1971 paper, “An algebraic definition of simulation between programs” . (That’s the official publisher’s version, but this tech report version seems to have more readable typesetting.) 1 Recently, though, I…