19. All m are x;
All m are y′.
20. No m are x;
All m′ are y.
21. All x are m;
Some m′ are y.
22. Some x are m;
All y are m.
23. All m are x;
Some y are m.
24. No x are m;
All y are m.
25. Some m are x′;
All y′ are m′.
26. No m are x′;
All y are m.
27. All x are m′;
All y′ are m.
28. All m are x′;
Some m are y.