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: That's just not how legal briefs are written. Sentence 2: That just isn't how legal reasoning works.
3

Sentence 1: Close-up of a hummingbird. Sentence 2: A closeup of a hummingbird flying.
4

Sentence 1: A bird sits in a tree. Sentence 2: A bird sits in a leafless tree.

4