發送短信 : On color fixing groups associated with colored symmetrical tilings

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