>>11so ML (and its derivatives), Lisp, and GHC Haskell (unsafePerformIO) aren't ``functional''? And don't say that they're ``mostly pure'' or that impurity is an edge case, it's boolean, either you have it, and you couldn't write an impure function if you wanted to, or you don't, and you can't assume that for
all functions, the purity property holds. If you can't assume it holds for all functions, then you generally get a much weaker property: there exist
some pure functions, something true of literally every single programming language in existence, including C, Java, etc.