發送短信 : Distribution solutions of some PDEs related to the wave equation and the diamond operator

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