發送短信 : Understanding variations (variant & invariant) of classification tasks/targets

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