anchor.diff:                      BLAS.daxpy(1., x, y')
                       y'
               // BLAS
  -            member o.Add_S_V(alpha, y) =
  -                if Array.isEmpty y then
  -                    Array.empty
  -                else
  -                    let alpha' = Array.create y.Length alpha
  -                    BLAS.daxpy(1., y, alpha')
  +            member o.Add_S_V(alpha, x) =
  +                if Array.isEmpty x then
  +                    Array.empty
  +                else
  +                    let alpha' = Array.create x.Length alpha
  +                    BLAS.daxpy(1., x, alpha')
                       alpha'
               // BLAS
               member o.Mul_S_V(alpha, x) =
  
positive.code:                     BLAS.saxpy'(1.f, x, y')
                      y'
              // BLAS
              member o.Add_S_M(alpha, y) =
                  if Array2D.isEmpty y then
                      Array2D.empty
                  else
                      let alpha' = Array2D.create (Array2D.length1 y) (Array2D.length2 y) alpha
                      BLAS.saxpy'(1.f, y, alpha')
                      alpha'
              // BLAS
              member o.Add_V_MCols(x, y) =
  
negative.code:                     BLAS.saxpy(1.f, x, y')
                      y'
              // BLAS
              member o.Add_S_V(alpha, x) =
                  if Array.isEmpty x then
                      Array.empty
                  else
                      let alpha' = Array.create x.Length alpha
                      BLAS.saxpy(1.f, x, alpha')
                      alpha'
              // BLAS
              member o.Mul_S_V(alpha, x) =
  