Tit-for -tat 纳什均衡,但不是精炼纳什均衡: (TFT,TFT)=T+8+827+637+…=7 1-δ (A-D,TFT)=T+8P+82P+δ3P+…=T+PTit-for-tat • 纳什均衡，但不是精炼纳什均衡：     − = + + + + = 1 1 (TFT, TFT) ... 2 3 V T T T T T      − = + + + + = + 1 (All - D,TFT) ... 2 3 V T P P P T P