[nigwil_]

I think it is worth mentioning that this was Robert Dewar's second or third Ada implementation (depending on how you want to count them). Robert was involved with the original Ada/Ed implementation from the late 1970s/early 1980s at NYU (targeting VAX minicomputers), and the re-implementation of that into a C-based implementation that ran on MS-DOS. Ada/Ed was the first validated Ada implementation, and it used SETL as its implementation language which Robert was actively involved in through the 1970s (so he had a long track record of language implementations).

What we are missing about the Ada story is the long line of languages and tools that inspired the Green design that lead to Ada, that is the language LIS (Pascal/Simula inspired) and its toolchain that Jean Ichbiah and associates used as inspiration for the Ada design.