發送短信

數:

提供者:

CAPTCHA:

 __   __     ___       _____   _    _    _____    
 \ \\/ //   / _ \\    / ___// | || | || |  __ \\  
  \   //   / //\ \\   \___ \\ | || | || | |  \ || 
  / . \\  |  ___  ||  /    // | \\_/ || | |__/ || 
 /_//\_\\ |_||  |_|| /____//   \____//  |_____//  
 `-`  --` `-`   `-` `-----`     `---`    -----`

Please enter what you see:

發送短信 : On semigroups of endomorphisms of a chain with restricted range