anchor.diff:                                          )
           leverage
           
  -    
  +
       /// Calculates the pseudo inverse of the matrix
       let pseudoInvers (matrix:Matrix<float>) =
           let (m,n) = matrixDims matrix
  
positive.code:             UpdateQ Q v
          Q,R
  
      let Hessenberg (A:matrix) =
          // REVIEW we can do with less copying here.
          let (n,m) = matrixDims A
  
negative.code:         (((*P.Length,*)Permutation.ofArray P),L + Matrix.identity nA,U)
          //(P, L + (Matrix.identity nA), U)
      
      /// Solves a system of linear equations, AX = B, with A LU factorized.
      let SolveLinearSystem (A:matrix) (b:vector) =
          let (n,m) = matrixDims A
  