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.

Sentence 1: Two dogs run side-by-side on the grass. Sentence 2: Two dogs running on grass.
4

Sentence 1: More expensive homes. Sentence 2: More expensive cars.
1

Sentence 1: Yes, they are both different. Sentence 2: Opinions are different.

1