rn_r
while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
t->rn_r = ttt;
x = x->rn_r;
x = x->rn_r;
x = x->rn_r;
p->rn_r = t;
t->rn_r = x;
t->rn_r = tt;
tt->rn_p->rn_r = tt;
if (tp->rn_r == tt)
x = tp->rn_r;
from->rn_p->rn_r = to;
to->rn_r->rn_p = to;
tp->rn_r = x;
x = tp->rn_r;
if (pp->rn_r == tp)
pp->rn_r = x;