TASK DEFINITION: In this task, you're given a pair of sentences, sentence 1 and sentence 2. Your job is to determine if the two sentences clearly agree/disagree with each other, or if this can't be determined. Indicate your answer as yes or no respectively.
PROBLEM: Sentence 1: Originally the post was simply an inter-city letter service. Sentence 2: The post used to be just for inter-city communications.

SOLUTION: yes

PROBLEM: Sentence 1: Batalha Abbey (see page 45) was built in gratitude. Sentence 2: As a showing of thanks, Batalha Abbey was constructed.

SOLUTION: yes

PROBLEM: Sentence 1: We have established that there was a book, in fact, three books.  Sentence 2: There are three books that were uncovered.

SOLUTION:
no