D O C U M E N T 9 0 O C T O B E R 1 9 2 5 1 0 5 We want to introduce the designations (11) in (10) as well. Additionally, we set [5] [this new relation is actually superfluous, because a comparison with (7) shows simply that ] and regard as the components of a three-dimen- sional vector a. Then one obtains out of (10) two equation triples (the one with the other with ), (to abbreviate ). Instead of (10) one can write and the two equation triples become In summary: and that means, If one defines as you have done, then these equations be- come and 2Γμμ μ gμμ----------- ∂gμμ ∂xμ – aμ = αμ 2ϕμ –= a1, a2, a3 μ 2, = ν 3 = μ 3, = ν 1 = μ 1, = ν 2 = μ 1 2 2, , , = v 4= Δ ∂2 ∂x ------- - ∂2 ∂y2 ------- - ∂2 ∂z2 ------- - + + = ∂xν ∂aμ ∂xμ ∂aν² – ¢ Δ ∂2 ∂t2¹ ------ -– © § · ψνμ ∂aμ ∂xν -------- - ∂aν ∂xμ -------- –= 15) ( Δ ∂2 ∂t2¹ ------· -– © § Ex ∂a2 ∂z -------- ∂a3 ∂y -------- –= Δ ∂2 ∂t2¹ ------· -– © § Ey ∂a3 ∂x -------- ∂a1 ∂z -------- ,–= Δ ∂2 ∂t2¹ ------· -– © § Ez ∂a1 ∂y -------- ∂a2 ∂x -------- –= ¿ ° ° ¾ ° ° ½ 16) ( Δ ∂2 ∂t2¹ ------· -– © § E rota –= ……(17) Δ ∂2 ∂t2¹ ------· -– © § Hx ∂a1 ∂t -------- ∂a4 ∂x -------- –= Δ ∂2 ∂t2¹ ------· -– © § Hy ∂a2 ∂t -------- ∂a4 ∂y -------- –= Δ ∂2 ∂t2¹ ------ -– © § · Hz ∂a3 ∂t -------- ∂a4 ∂z -------- –= ¿ ° ° ¾ ° ° ½ 18) ( Δ ∂2 ∂t2¹ ------· -– © § H a · grad a4 –= ……(19) aμ 0 d. h. ϕμ 0= ( ), = Δ ∂2 ∂t2¹ ------ -– © § · E 0= ………(20) Δ ∂2 ∂t2¹ ------ -– © § · H 0= ………(21)