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List Structure

first rest

Lists are a basic data structure in Lisp; in fact, Lisp code is made of lists. The external (printed) representation of lists is a sequence of elements enclosed in parentheses.

(first '(a b c))      =  A

(rest '(a b c))       =  (B C)

(second '(a b c))     =  B

(cons 'z '(a b c))  =  (Z A B C)

(list 'a 'b 'c)       = (A B C)
first is also called car; rest is also called cdr.

The quote symbol ' is a shorthand for the pseudo-function quote. (quote x) = x, that is, quote returns the argument itself rather than evaluating the argument.