R4RS 6.3  (cons object1 object2)  ==>  pair

Returns a newly allocated pair whose car is OBJECT1 and whose cdr
is OBJECT2. The pair is guaranteed to be different (in the sense
of EQV?) from every existing object.

(cons 'a '())         ==>  (a)
(cons '(a) '(b c d))  ==>  ((a) b c d)
(cons "a" '(b c))     ==>  ("a" b c)
(cons 'a 3)           ==>  (a . 3)
(cons '(a b) 'c)      ==>  ((a b) . c)
