That's mostly subjective, (a,b, °c) is a tuple of a, b and the rest being the sequence c. After reading a lot of lisp and ml, it's a bit less of a burden than [a,b] + l, in the sense that [a,b] is declarative mixed with an operation, while (a,b, °c) is one declarative. You might say `°` is an operation too, but it lives at the metalevel, and it's still enclosed in the (tuple-declaration).