Sentence 1: He can use his brains, that young fellow.

Sentence 2: He is stupid and doesn't use his brain at all.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: A great pity, agreed Poirot gravely.

Sentence 2: That's unfortunate, agreed Poirot.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: Reaching around back he drew his off-hand dagger from the sheath at the small of his back and another blade from the top of his left boot.

Sentence 2: He went to pull a blade out from his left boot but it was missing.
Is this second sentence entailed by the first?

Answer:
no