The combinators (operators on the stack) are often limited to 1, 2 or 3 parameters picked on the top of the stack.

In Lisp you can write (+ 1 2 3 ... n).

With a stack-based language, you might write:

    1 //push 1
    2 //...
    3 
    + //add 3,2 and push 5
    + //add 5,1 and push 6