Have we become a bit complacent about RT?
We're not complacent, we just know things without having to check references. Just kidding, of course, functional programmers tend to enjoy improving their understanding!-) The Strachey reference is worth reading - great that it is online these days, but it can be useful to complement it with others. Before Quine, there was Carroll, who explored meaning [1] and referential opacity [2], among other things. Also useful is Sondergaard and Sestoft [3], which explores both the history and the differences between not-quite-equivalent definitions. I happen to disagree with Reddy's assertion that having to explain a complicated language with the help of a less complicated one is perfectly adequate. Reddy himself has done good work on semantics of programming languages, but I'm a programmer first - if the language I work with does not give me the qualities that its semantics give me, then my means of expression and understanding are limited by the translation. All to be taken with grain of salt, active mind and sense of humor. Claus [1, Chapter 6] http://en.wikiquote.org/wiki/Through_the_Looking-Glass [2, the name of the song] http://homepages.tcp.co.uk/~nicholson/alice.html [3] Søndergaard, Sestoft (1990). "Referential transparency, definiteness and unfoldability". Acta Informatica 27 (6): 505-517. http://www.itu.dk/people/sestoft/papers/SondergaardSestoft1990.pdf