Question: Sentence A: And then, suddenly, a dreadful possibility flashed through my mind.

Sentence B: A beautiful thought popped into my mind suddenly.

If sentence A is true, how about sentence B?

Answer: no

Question: Sentence A: Including the red Curtiss biplane.

Sentence B: The red biplane was included in the plans to take off on a mission.

If sentence A is true, how about sentence B?

Answer: it is not possible to tell

Question: Sentence A: Then I remembered that enigmatical conversation between Poirot and Evelyn Howard.

Sentence B: A previous conversation between Poirot and Evelyn Howard came to my mind.

If sentence A is true, how about sentence B?

Answer: yes

Question: Sentence A: Cuba Libre , by Elmore Leonard (Delacorte).

Sentence B: Cuba Libre is a book about Cuban revolutionaries.

If sentence A is true, how about sentence B?

Answer:
it is not possible to tell