fliplist
yytree = fliplist(yytree);
$2->n_ufunc = node(DEFFUNC, $5, fliplist($9));
static NODE * fliplist ANSI((NODE *np));
np->n_right = fliplist(np->n_right);
lp->n_right = fliplist(lp->n_right);
np->n_left = fliplist(np->n_left);