lobsters are selfish.
- All x are y'. i.e. All lobsters are unselfish.
- Some x are y, and some are y'. i.e. Some lobsters are selfish, and some are unselfish.
- All y' are x'. i.e. All invalids are unhappy.
- Some y' exist. i.e. Some people are unhealthy.
- Some y' are x, and some are x'. i.e. Some invalids are happy, and some are unhappy.
- No y' exist. i.e. Nobody is unhealthy.
- Smaller Diagram.
Propositions represented.