Cons Cells

• cons means "construct"
• car: address register
• cdr: document register

Recursively construct a list in order:

(cons 1 (cons 2 (cons 3 nil)))

Cons a list with another list:

(cons '(1 2) '(3 4))

Cons two cons cells:

(cons (cons 1 2) (cons 3 4))

((1 . 2) 3 . 4)

(cons (cons 1 (cons 2 3)) 4)

((1 2 . 3) . 4)

(cons (cons 1 2) (cons (cons 3 4) nil))

((1 . 2) (3 . 4))

(cons 1 (cons 2 (cons 3 4)))

(1 2 3 . 4)