1 sew(turn(sew(B,turn(B))),
2 turn(sew(turn(B),B))) ;
5 sew(turn(sew(B,turn(B))),A);
6 sew(turn(sew(A,turn(A))),
9 turn(sew(A,turn(A))))))
13 sew(turn(sew(B,turn(B))),
14 turn(sew(turn(B),B))) ;
17 sew(turn(sew(B,turn(B))),A);
18 sew(turn(sew(A,turn(A))),
21 turn(sew(A,turn(A))))))