3, 4), fk h = -fk h,
Therefore
f₃₂ = -f₂₃, f₁₃ = -f₃₁, f₂₁ = -f₁₂
f₄₁ = -f₁₄, f₄₄ = -f₂₄, f₄₃ = -f₃₄
Then the three equations comprised in (i), and the equation (ii) multiplied by i becomes
"Formula A."
On the other hand, the three equations comprised in (iii) and the (iv) equation multiplied by (i) becomes