� � ӭ ʹ � � u е � � ƻ � � � � mu �

14 � � � � � �Ŀ fell

14.1 � � � �

� � � � � � ɻ � � � � � � � Ҫ � � � ֮ һ � � � � � � � Ҫ � � � � � � ֧ � � � � ת � � � � � � � � � ת � غ � � ˶ � � �

һ � � � � ķ � � �

1. � � � ᣺ � � � � ֧ � � ת � � � � � � � ֻ � � � � � � ض � � � � � � � ת � ء � � � � � � � � f � � � ǰ � � � ᡣ

2. � � � � � ᣺ � � Ҫ � � � ڴ � � � ת � ض � � � � � � � � � أ � � � � � � � � ܵ � � � غ � С � � � ᡣ

� � � � � � � � � � � � � ӱ � � � � � � � � � � ֮ � � � � ᡣ

3. ת�᣺������������ᣬͨ�����Ϊ�ᡣ����ʱ�ȳ�������ֳ���ת�ء�

14.2 � � Ľ ṹ � � �

һ � � � � � � � � � � Ĺ ̶ �

� � � � � � � � Ĺ ̶ � � � Ϊ � � � � ̶ � � � � � � � ̶ � � � � ֡ �

� � 綨 lambda � �

� ɲ � � Ĺ � � � � � е � � � � � � � � � � � ṹ ͼ � � � � � ǰ � � � � ˴ � � � � ʽ � �

� � � � � � � � � � � � � װ � � � � � � ļ ӹ � Ҫ � �

� � � � � � � � � � ǿ � Ⱥ ͸ ն ȣ � � � Լ � � � Ϻ ͼ � � � � � � �

Ŀ fell� � һ � �� ´ &western Σ � � � ǿ � ȼ � � 㣩