added comments on BLEU score evalutaion. the BLEU score can be higher than true BLEU score because the context is from the reference's past response, instead of the true response from the decoder
added comments on BLEU score evalutaion. the BLEU score can be higher than true BLEU score because the context is from the reference's past response, instead of the true response from the decoder

kaishengyao/cnn,kaishengyao/cnn