Bivalent BAM theorem △L=-△S(X)MS(Yk)'-△S(X)[I-U] =-AS(X)IS(Y)M-U =-∑∑AS,(,)S,0y)m∑AS,(x)山，+∑AS,(x,U -∑As,(G∑S0ym,-∑aSx川，+∑As, =-∑AS,(x)∑S,)m,+1,-U] =-AS,(x,Ix41-U月 88 Bivalent BAM theorem T T L = −S(X)MS(Yk ) − S(X) [I −U] T T = −S(X)[S(Yk )M −[I −U]] = − − + i i i i i i i i i j i j k T Si xi S j y m S x I S x U j ( ) ( ) ( ) ( ) = −  − + i i i i i i i i i j i j k T Si xi S j y m S x I S x U j ( ) ( ) ( ) ( ) ( )[ ( ) ] i i i j i j k T Si xi S j y m I U j = −  + − ( )[ ]i i k = −Si xi xi −U +1  0