This is really interesting - I didn't know about that snippet of Lisp history. So the expression we'd write today as (car (append '(a b c) '(

This is really interesting - I didn't know about that snippet of Lisp history. So the expression we'd write today as (car (append '(a b c) '(d e f))) Would originally have been written in M-expression form as car[append[(a b c); (d e f)]] Programming in Lisp might be a very different experience if M-expressions had caught on!