أرسل هذا في رسالة قصيرة: The compound equation related to the Bessel-Helmholtz equation and the Bessel-Klein-Gordon equation

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