+(put 'unless 'lisp-indent-function 1)
+(put 'unless 'edebug-form-spec '(&rest form))
+
+(defsubst caar (x)
+ "Return the car of the car of X."
+ (car (car x)))
+
+(defsubst cadr (x)
+ "Return the car of the cdr of X."
+ (car (cdr x)))
+
+(defsubst cdar (x)
+ "Return the cdr of the car of X."
+ (cdr (car x)))
+
+(defsubst cddr (x)
+ "Return the cdr of the cdr of X."
+ (cdr (cdr x)))
+
+(defun last (x &optional n)
+ "Return the last link of the list X. Its car is the last element.
+If X is nil, return nil.
+If N is non-nil, return the Nth-to-last link of X.
+If N is bigger than the length of X, return X."
+ (if n
+ (let ((m 0) (p x))
+ (while (consp p)
+ (setq m (1+ m) p (cdr p)))
+ (if (<= n 0) p
+ (if (< n m) (nthcdr (- m n) x) x)))
+ (while (cdr x)
+ (setq x (cdr x)))
+ x))
+
+(defun assoc-default (key alist &optional test default)
+ "Find object KEY in a pseudo-alist ALIST.
+ALIST is a list of conses or objects. Each element (or the element's car,
+if it is a cons) is compared with KEY by evaluating (TEST (car elt) KEY).
+If that is non-nil, the element matches;
+then `assoc-default' returns the element's cdr, if it is a cons,
+or DEFAULT if the element is not a cons.
+
+If no element matches, the value is nil.
+If TEST is omitted or nil, `equal' is used."
+ (let (found (tail alist) value)
+ (while (and tail (not found))
+ (let ((elt (car tail)))
+ (when (funcall (or test 'equal) (if (consp elt) (car elt) elt) key)
+ (setq found t value (if (consp elt) (cdr elt) default))))
+ (setq tail (cdr tail)))
+ value))