anchor.diff:      let inline laplacian' f (x:_[]) =
           let i = GlobalTagger.Next
           let a = Array.init x.Length (fun j ->
  -                                        let xd = standardBasis x.Length j |> Array.map2 (makeDFIPT i) x
  +                                        let xd = standardBasis x.Length j |> Array.map2 (makeDFipt i) x
                                           fVStoSS j f xd
                                           |> diff
                                           <| xd.[j])
  
positive.code:     /// Original value and gradient-vector product (directional derivative) of a vector-to-scalar function `f`, at point `x`, along vector `v`
      let inline gradv' f x v =
          let i = GlobalTagger.Next
          Array.map2 (makeDFIPT i) x v |> f |> tuple
  
      /// Gradient-vector product (directional derivative) of a vector-to-scalar function `f`, at point `x`, along vector `v`
      let inline gradv f x v =
  
negative.code:     /// Original value and Jacobian-vector product of a vector-to-vector function `f`, at point `x`, along vector `v`
      let inline jacobianv' f x v =
          let i = GlobalTagger.Next
          Array.map2 (makeDFipt i) x v |> f |> Array.map tuple |> Array.unzip
  
      /// Jacobian-vector product of a vector-to-vector function `f`, at point `x`, along vector `v`
      let inline jacobianv f x v =
  