And there is an ancestral relationship. Chuck Moore (the inventor of Forth) studied under McCarthy directly. https://news.ycombinator.com/item?id=18228381

I think it’s indeed LOP. > Forth has been called a language tool-kit. It is the starting point for an application language, much as the infant brain has the ability to learn any human language. https://www.red-gate.com/simple-talk/opinion/geek-of-the-week/chuck-moore-geek-of-the-week/