So if you have
(def foo (a b . c) ...stuff...)
and you call (foo 1 2 3 4 5), a is bound to 1, b is bound to 2, and c is bound to the list (3 4 5).
And
(def foo a ...stuff...)
is just shorthand for
(def foo ( . a) ...stuff...).
So calling (foo 1 2 3) in this case means a is bound to the list (1 2 3).
