Sentence 1: It's as though their melancholy derived from the excruciating imperative to be blacks performing according to the conventions of blackface.

Sentence 2: The actors were not happy to be performing in blackface.
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: Some goods are produced more cheaply in the United States than abroad.

Sentence 2: The US can sometimes produce cheap goods.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: His lasting legacy was the invention of coinage, which led to the beginnings of our money-based economy.

Sentence 2: He was responsible for the creation of the first coins.
Is this second sentence entailed by the first?

Answer:
yes