TASK DEFINITION: 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.
PROBLEM: Sentence 1: The man drilled holes into the wood. Sentence 2: A man drills wood.

SOLUTION: 4

PROBLEM: Sentence 1: US Cannot 'Conclusively Determine' Chemical Weapons Use in Syria Sentence 2: U.S. Sees No Conclusive Evidence of Chemical Arms Use by Syria

SOLUTION: 5

PROBLEM: Sentence 1: The Dow Jones industrial average .DJI was off 58.69 points, or 0.64 percent, at 9,137.86. Sentence 2: The blue-chip Dow Jones industrial average .DJI fell 86.56 points, or 0.94 percent, to 9,109.99, after giving up more than 1 percent earlier.

SOLUTION:
2