The first encounter I had with automatic differentiation was in a simulation language called PROSE, circa 1974. I never actually used it, but I came across a ma

The first encounter I had with automatic differentiation was in a simulation language called PROSE, circa 1974. I never actually used it, but I came across a manual for it, which I found quite fascinating. As I recall, it ran on the CDC 6000 series -- at the time I was doing numerical physics on a 6400, and PROSE was being presented as an alternative to the ubiquitous FORTRAN. PROSE seems to have been completely forgotten; I can find nothing on it now. But I distinctly recall that it did AD. Everything in computer science was invented before 1980 :-)