ָ: Ychl           

:  ʾƼԸ
                         
λ: 
   1 ʽܱ          Y   ->  ͼʾ
   2              Y_趨  ->  ͼʾ

: 
  1 ȫʾ -- ͼ   (ʹ, ָ all_lay)

  2 ֲʾ -- ѡҪʾ֮ͼ,ͼر   (ʹ, ָ show_lay)
        a1. ֱѡȡ(ɶѡȡ) ,ֻʾ,ر
        a2. Enter (ѡȡ), ֻѡȡ,ر
        ****δѡȡҲر****

  3 ʾ -- ڹرͼѡҪ׷ʾ֮ͼ  (ʹ, ָ add_lay)

  4 ʾ -- ѡҪ׷ӹر֮ͼ   (ʹ, ָ off_lay)
        a1. ֱѡȡ(ɶѡȡ) ,ʾ,㲻
        a2. Enter (ѡȡ), ֻѡȡ,㲻
        ****ѡȡҲر****

  5 -- סͼ,ɾ   (ʹ, ָ lock_lay)

  6  -- ⿪סͼ   (ʹ, ָ unlock_lay)

  7 ͼ   (ʹ, ָ new_lay)
  
  8 任: (ͼ,,ɫ)    (ʹ, ָ chg_lay)
     a1. ѡȡ,ɶѡȡ,Enterѡȡ -> Enterͼѡ/<ѡȡͼ>:
     a2. ѡȡͼѡ---ѡȡͼ(ѡⲻڲ)
     a3. ѡȡ
       a.  -- ֻͼ , Ͳ.
       b.  -- ڶ , (Bylayer).
       c. ʵ -- ʵ(Continuous).
       d.  -- (Center).
       e.  -- (Hidden).
       f.  -- ͼ(Phantom).

     a4. ѡȡɫ -- 1 ~ 256
