_f_ = | 0 _f₁₂_ _f_₁₃ _f₁₄_ |
| _f_₂₁ 0 _f₂₃_ _f₂₄_ |
| _f₃₁_ _f_₃₂ 0 _f₃₄_ |
| _f_₄₁ _f_₄₂ _f_₄₃ 0 |
in which the elements fulfil the relation _f__{_h_ _k_} = -_f__{_h_
_k_}, is called an alternating matrix. These relations say that the
transposed matrix _ḟ_ = -_f_. Then by _f_^{*} will be the _dual_,
alternating matrix
(35)
_f_^{*} = | 0 _f₃₄_ _f_₄₂ _f₂₃_ |
| _f_₄₃ 0 _f₁₄_ _f₃₁_ |
| _f₂₄_ _f_₄₁ 0 _f₁₂_ |
| _f_₃₂ _f_₁₃ _f_₂₁ 0 |