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: Mr Colpin did not specify whether it was this system that was at the centre of the investigation. Sentence 2: Neither OLAF nor the Belgian prosecutors have specified if it was this system that was at the centre of the investigation.

SOLUTION: 2

PROBLEM: Sentence 1: Philippines defers comment on Taiwan fisher attack Sentence 2: Bin Laden's continuing sway shown in Kenya mall attack

SOLUTION: 0

PROBLEM: Sentence 1: The broader Standard & Poor's 500 Index <.SPX> gave up 11.91 points, or 1.19 percent, at 986.60. Sentence 2: The technology-laced Nasdaq Composite Index .IXIC declined 16.68 points, or 1.01 percent, at 1,636.94.

SOLUTION:
1