rn_l
x = x->rn_l;
x = x->rn_l;
t = t->rn_l;
t->rn_l = tt;
x = x->rn_l;
tt = t->rn_l;
p->rn_l = t;
t->rn_l = x;
if (x->rn_l == t)
x->rn_l = tt;
x = t->rn_l;
if (t->rn_l == tt)
t->rn_l = x;
if (p->rn_l == t)
p->rn_l = x;
x->rn_l->rn_p = x;
if (t->rn_l == tt)
x = t->rn_l;
p->rn_l = x;
t->rn_l->rn_p = t;
if (p->rn_l == x)
p->rn_l = t;
rn = rn->rn_l;
rn = rn->rn_l;
tt = t->rn_l;