Text this: Solving sparse linear systems by an abs-method that corresponds to LU-decomposition

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