Cool, awesome, great point. I tried Googling for your implementation and couldn't find it. Could you drop a link?

Yes, the arithmetic primitives don't support variadic arguments. You can see how + works - and that it only deals with the first two arguments - here: https://github.com/alandipert/gherkin/blob/278354246aebf14b8.... A pull request fixing this would be welcome.

In the meantime, for variadic addition, one can do:

(load-file "core.gk") (reduce + 0 '(1 2 3)) ;=> 6