It means, literally: call a function named '>' and pass it the three arguments specified. That's it. You may ask what does the function > do when called, but t

It means, literally: call a function named '>' and pass it the three arguments specified. That's it. You may ask what does the function > do when called, but that's a different question and has nothing to do with a language's syntax and semantics. Also, it's exactly the same with non-Lisp languages. If you don't know Python and see a fragment of code like this: 2 ^ 3 ** 3 wouldn't you have to ask the same question, ie. what do the operators `^` and the other one do when used? However, in this case, you need to also ask about the precedence of the operators, which doesn't exist in Lisp.