用于句子相似性检测的BLEU分数实现

I need to calculate BLEU score for identifying whether two sentences are similar or not.I have read some articles which are mostly about BLEU score for Measuring Machine translation accuracy.But i'm in need of a BLEU score to find out similarity between sentences in a same language[English].(i.e)(Both the sentences are in English).Thanks in anticipation.I need to calculate BLEU score for identifying