by S.Yu. Orevkov

Using Murasugi-Tristram inequality for auxiliary braids, we prove that the following isotopy types of M-curves of degree 9 are not realizable:

< J U b U 1< 1< a >>> ,      where   a + b = 26   and   b = 0,1,2,3,4,5,6,8,10,12,14,16,18,20,22,24.

In the same way we show that the complex scheme of an M-curve of degree 7 cannot be

< J U 10+ U 3_ U 1_< 1_ >> .

These results and some others are proved with more detail and less mistakes in the paper "Plane real algerbaic curves of odd degree with a deep nest".