Sentence 1: Doubtless the writer was interrupted; but there can be no question as to his identity.

Sentence 2: It's obvious the writer was interrupted, but his identity is clear.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: you're kidding me

Sentence 2: You are being completely serious.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: I thought he was making it up."

Sentence 2: I thought he was making it up.
Is this second sentence entailed by the first?

Answer:
yes