發送短信 : On metric spaces of subcopulas

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