Text this: Boundary value problem of the operator ⊕<sup>k</sup>related to the biharmonic operator and the diamond operator

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