47  * node to the root of the tree and partly rebalances it.
59  *	- every search path from the root to a leaf consists of the
61  *	- each red node (except for the root) has a black parent,
70 	struct type *sph_root; /* root of the tree */			\
73 #define SPLAY_INITIALIZER(root)						\  argument
76 #define SPLAY_INIT(root) do {						\  argument
77 	(root)->sph_root = NULL;					\
304 	struct type *rbh_root; /* root of the tree */			\
307 #define RB_INITIALIZER(root)						\  argument
310 #define RB_INIT(root) do {						\  argument
311 	(root)->rbh_root = NULL;					\
348  * Something to be invoked in a loop at the root of every modified subtree,
349  * from the bottom up to the root, to update augmented node data.
429  *  elm (could be the root)