Yeah, but it's not possible (I think, but am not 100% sure) to reason about F# code without object semantics because of how it's implemented: it probably could

Yeah, but it's not possible (I think, but am not 100% sure) to reason about F# code without object semantics because of how it's implemented: it probably could be implemented on top of MSIL without objects, but (again, not 100%, but 95% sure :)) it isn't. I thought about another language I think you'd call functional: Lua. It supports first- and higher-order functions and has no objects at all in the core language. What do you think? Also, now that I understand what you mean I can agree with you, but you do realize that this is not very common definition of "functional", right? :)