Term

Definition

Example

Atoms

Like types: the fundamental items formed from bits

27, 3.14, This-Phrase

Lists

Sentence like objects containing atoms or other lists.

'(this that the other thing)

Symbolic expressions / or [s-]expressions

Atoms and lists collectively are called expressions.

setf

(setf <name> <list>) creates a set called <name> that has the value <list>

(setf friends '(Dan Randy))

Data Types

See Figure 1

FIRST

(FIRST LIST) returns the first expression in the list

(FIRST (A B C)) --> A

REST

(REST LIST) returns the expression after the first element of the list as a list

(REST (A B C)) --> (B C)

QUOTE

'(I J) will return a list with the elements I and J without trying to interpret I as a function

'(A B C) --> (A B C)

 

                     |Number
                     |
             |Atom---|
             |       |
Expressions -|       |Symbol
             |
             |LIST

Figure 1