發送短信 : Verification & discretization of the index theorem for a two dimensional dirac operator

            _____    __   _     ______   ______   
  ____     |  ___|| | || | ||  /_   _// |      \\ 
 |    \\   | ||__   | '--' ||   -| ||-  |  --  // 
 | [] ||   | ||__   | .--. ||   _| ||_  |  --  \\ 
 |  __//   |_____|| |_|| |_||  /_____// |______// 
 |_|`-`    `-----`  `-`  `-`   `-----`  `------`  
 `-`