I agree that "properly working lambda expressions were only available in Lisp until recently" is perfectly idiomatic, but easily misunderstood, English. I believe that the suggested fix "properly working lambda expressions were only available in Lisp since recently," which is what I was responding to, is not idiomatic. Claims about what is and isn't idiomatic aren't really subject to definitive proof either way, but it doesn't matter, because the suggester now agrees that it is not what was meant (
https://news.ycombinator.com/item?id=43653723).