Motivating Puzzle
Someone who lives in Dreadbury Mansion killed Aunt Agatha.
Agatha, the butler, and Charles live in Dreadbury Mansion, and are the only people who live
therein.
The police needed to determine: Who killed Aunt Agatha?
The following facts are known about killers and the people who live in the mansion:
- A killer always hates their victim.
- A killer is never richer than their victim.
- Charles hates no one that Aunt Agatha hates.
- Agatha hates everyone except the butler.
- The butler hates everyone not richer than Aunt Agatha.
- The butler hates everyone Aunt Agatha hates.
- No one hates everyone.
Automated Theorem Proving was used to analyse this issue, and it turned out that
...
Agatha committed suicide.
The
TPTP version