(+ z₁ z₂ ... z_n)
(- z₁ z₂ ... z_n)
(* z₁ z₂ ... z_n)
(/ z₁ z₂ ... z_n)
Returns z₁ {+|-|*|/} z₂ {+|-|*|/} ... {+|-|*|/} z_n.

(eq s₁ s₂ ... s_n)
(= s₁ s₂ ... s_n)
Returns t if the s_i are all the same object, nil otherwise.

(< z₁ z₂ ... z_n)
(> z₁ z₂ ... z_n)
Returns t if the z_i are in ascending or descending order, respectively, or nil otherwise.

(and s₁ s₂ ... s_n)
(or s₁ s₂ ... s_n)
Returns t if the s_i are all non-nil (and) or if any s_i is non-nil (or). Evaluates arguments from left to right and stops when the return value is determined.

(cond (p₁ [s₁]) (p₂ [s₂]) ... (p_n [s_n]))
Evaluates the p_i left to right. When one is found to be non-nil, if the corresponding s_i exists, it is returned; otherwise, the value of p_i itself is returned. If no p_i is non-nil, then nil is returned.

(car s)
Returns the first element of the list s. If s is not a list, returns nil.

(cdr s)
Returns the tail of the list s, i.e. s with its first element removed. If s is not a list, returns nil.

(cons e s)
Returns a new list whose car is e and whose cdr is s.

(atom s)
Returns t if s is an atom (i.e. not a list), nil otherwise.

(list s₁ s₂ ... s_n)
Returns a list whose elements are the (evaluated) s_i.

(quote s)
Returns s uninterpreted.

(set e s)
Sets e to the evaluated value of s. The value of e must be a symbol, i.e. [a-z][a-z0-9]*.

(print s)
Outputs, through a Javascript window, the s-exp s and returns (passes through) s.

(eval s)
Evaluates s and returns the result.

(define a l e)
Describes a new function named a with arguments l defined by the expression e.

(lambda (a₁ a₂ ... a_n) s₁ s₂ ... s_m)
When used at the head of a list, assigns the next n elements of the list to the symbols a_i and then evaluates the s_i in order, returning the value of s_m.

In addition, the following are defined as composite functions; i.e. they're defined in Lisp itself as functions of the above primitives.

The standard car and cdr composites cadr, cddr, caar, cddr, cadar, cddar, cdadr, caddr.

(null s)
(not s)
Returns t if s is nil, nil otherwise.

(equal x y)
Tests equality, where equality of lists means structural equality, not that they are the same object as with eq.