Adaptation (one stable fixed point) y sf1 x,y ,"的+2rnk, 4 eff eff 2 X x=0 x k,+kru)x+k eff e2少 x ff 2.y x pt eff in pt eff eff in y k x k y r x k k x k y r = − + = − + + + 2 4 2 ( ) & & y & = 0 x & = 0 ⎟⎟⎠⎞ ⎜⎜⎝⎛ + = ( ) 2 , 2 ( , ) 4 2 4 4 * * k k L r k r k k r x y eff eff in eff in pt effin Adaptation (one stable fixed point) sfp 5