For context, the first FORTRAN compiler was delivered in 1957[1] and LISP in 1958[2].
My eye was caught by this remark, a propos the careful specification of Algol 60's syntax,
> indeed many early languages were virtually defined by the action (not always predictable) of their compilers.
But they immediately qualify that with
> Unfortunately the rigour with which the syntax of ALGOL is defined does not extend to the semantics...
[1] https://en.wikipedia.org/wiki/Fortran#History
[2] https://en.wikipedia.org/wiki/Lisp_(programming_language)#Hi...