**''LAMBDA''**

''LAMBDA'' form defines and returns an unnamed function object. Apart from that, syntax is the same as ''DEFUN''. First argument must be a list of parameters (symbols) of the function, the symbols are not evaluated. Second argument is optional description string. If the second argument is not string, it is considered first form of the function body. Any other parameters are to ''LAMBDA'' are stored as the function body.  

<code lisp>
>(lambda (a b) (+ a b))   ; lambda call
#<user-defined lambda>    ; function object was returned                
</code>

The ''LAMBDA'' form can be used in place of the operator.

<code lisp>
>((lambda (a b) (+ a b)) 3 5)   ; defined the lambda and immediately used on 3 5
8                
</code> 

In this example we have created unnamed function object in the first position of the whole form, so it gets applied to the numbers 3 and 5. 

The function objects created by the ''LAMBDA'' forms can be stored somewhere and called later without the need for a name.

<code lisp>
>(setq ops (cons             ; define symbol OPS and its value will be a cons-cell
   (lambda (a b) (+ a b))     ; function for addition is in the CAR
   (lambda (a b) (- a b)) )   ; function for subtraction is in the CDR
(#<user-defined lambda> . #<user-defined lambda>)

>((car ops) 4 7)             ; using the adding function
11

>((cdr op) 4 7)              ; using the subtraction
-3
</code>

Parameter list of ''LAMBDA'' can have ''&OPTIONAL'' and ''&REST'' parameters just like the named functions (see ''DEFUN'').

The functions created by ''LAMBDA'' have lexical closure also like the named functions.