Evaluate the similarity between them and classify them into classes from 0-5 as follows:
0 : The two sentences are completely dissimilar.
1 : The two sentences are not equivalent, but are on the same topic.
2 : The two sentences are not equivalent, but share some details.
3 : The two sentences are roughly equivalent, but some important information differs/missing.
4 : The two sentences are mostly equivalent, but some unimportant details differ.
5 : The two sentences are completely equivalent, as they mean the same thing.

[EX Q]: Sentence 1: A cat is playing the piano. Sentence 2: A cat is licking its paw.
[EX A]: 0

[EX Q]: Sentence 1: A man riding a white horse in an arena. Sentence 2: A man riding a white horse.
[EX A]: 4

[EX Q]: Sentence 1: Iran is also a signed of the NPT and the IAEA. Sentence 2: Gotta love the EK factoid that "Iran is also a signed of the NPT and the IAEA.
[EX A]:
4