A number of sleuths (the player among them) find themselves aboard the Orient Express, where a murder has taken place, and one of them is apparently the culprit. Naturally they do not agree on whom, but there is physical evidence which may change their minds…

The following example creates two new relations, and two new verbs, in order to set up a tangled web of intrigue.

"Murder on the Orient Express"
The Dining Car is a room. Lord Peter is a man in the Dining Car. Sherlock Holmes is a man in the Dining Car. Miss Marple is a woman in the Dining Car. Adam Dalgliesh is a man in the Dining Car.
Suspecting relates various people to one person.
The verb to suspect means the suspecting relation.
Dalgliesh suspects Holmes. Holmes suspects Lord Peter. Lord Peter suspects Holmes. Miss Marple suspects the player.
Exculpating relates one thing to various people.
The verb to exculpate means the exculpating relation.
The silver bullet exculpates the player. The pipe ash exculpates Holmes. The poison pen letter exculpates Lord Peter. The poison pen letter exculpates Miss Marple. [Poor Dalgliesh. I guess he did it.]
The pipe ash, the letter and the silver bullet are carried.

Given this, we can then set up elaborate rules:

Instead of showing something to a person who suspects the player:
   say "'You would say that,' remarks [the second noun] darkly.".
Instead of showing something which exculpates the player to someone:
   say "'How striking!' says [the second noun]. 'Almost I begin to distrust myself.'".
Test me with "show the letter to miss marple / show the silver bullet to holmes".
Test me with "show the letter to miss marple / show the silver bullet to holmes".
Dining Car
You can see Lord Peter, Sherlock Holmes, Miss Marple and Adam Dalgliesh here.

>(Testing.)

>[1] show the letter to miss marple
"You would say that," remarks Miss Marple darkly.

>[2] show the silver bullet to holmes
"How striking!" says Sherlock Holmes. "Almost I begin to distrust myself."

And so on: "if Dalgliesh suspects someone who is exculpated by something carried by the player…", for instance, makes a fitting final example for this chapter. The description

someone who is exculpated by something carried by the player

expresses a complicated idea in very few words, and in such a way that a passer-by looking at the source text would immediately see what was meant.

The moral is that relations allow sophisticated patterns of behaviour to be created in a way that reads back naturally as English.