A Challenge Theorem
Garfield is a cat and Odie is a dog.
Cats and dogs are pets.
Jon is a human.
Every pet has one human owner.
Jon owns Garfield and Odie, and they are the only cat and dog he owns.
If a dog chases a cat, then the cat's owner hates the dog's owner.
Odie has chased Garfield.
Therefore, Jon hates himself.
Another Challenge Theorem
Every student is enrolled in at least one course.
Every professor teaches at least one course.
Every course has at least one student enrolled.
Every course has at least one professor teaching it.
The coodinator of a course is a professor who is teaching it.
If a student is enrolled in a course then the student is taught by every professor who teaches
the course.
CSC410 is a course.
Michael is a student enrolled in CSC410.
Victor is the coordinator of CSC410.
Therefore, Michael is taught by Victor.