Sentence 1: caused by an increase in volume would be small.

Sentence 2: Mail volume needs to be increased
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: In any case--it's over."

Sentence 2: It is over.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: Come now, he continued, as Tuppence remained silent.

Sentence 2: Tuppence did not remain silent, he shouted instead.
Is this second sentence entailed by the first?

Answer:
no