Model

BLEU-1/2/3/4

F1

BERT-Score

P-Cover

P-EM

S2SA

28.80/9.32/2.50/0.56

31.80

0.103

25.49

72.67

PGN

31.00/12.13/4.86/1.96

33.17

0.119

26.52

73.40

Transformer

34.47/23.11/16.93/12.71

40.25

0.357

36.69

85.24

TransferTransfo

37.66/26.36/20.24/15.89

41.01

0.368

40.33

85.95

LIC

34.86/23.64/17.46/13.19

42.64

0.387

31.95

84.18

BERT2BERT

38.15/26.99/20.76/16.24

45.66

0.417

36.69

85.45

BERT-HCM

39.59/28.69/22.59/18.08

46.01

0.423

40.58

86.25