D O C . 9 1 R E L AT I V I T Y & E Q U AT I O N S O F M O T I O N 9 7 (6) [17] plays a twofold role in forming (1). Considering (2a), (3a), and (6), one finds in place of (1) the two systems (7) . (8) [18] and refer to the linear operator (6), applied to or to , resp. For , we find the following expression using (2a), (3a), and (7): (9) [19] The Maxwell equations (4) are required for the following only to the first ap- proximation, since in (8) and (9), only the enter, but not the , and then—as I have convinced myself—equations (4) can always be satisfied to second order without any relevant limiting conditions for the problem of motion. Thus, instead of (4), we have to put (10) [20] What we have carried out up to now is simply a rearrangement of the field equa- tions for gravitation. The further investigation makes use of (7) and (8), and can be characterized as follows: We determine and in accord with equations (7) and (10), by seeking a solution with a pointlike, centrally symmetric singularity and external gravitational and electromagnetic fields. Through this solution, the in (8) are then also determined. The main goal now consists of answering the following question: Which condition must be fulfilled by the solution in the first approximation so that quantities exist that have no new singularities, and thus in particular are regular in the neighborhood of a singular point?[21] Before we answer that question, we want to demonstrate the solution in first ap- proximation and choose a coordinate system that is suited to our considerations. L i i   i  – = L i 0 = L i Q i + 0 = L i L i g i g i Q i Q i  x  g  i        x  g  i       + i    i    – – = 1 4 –  i   2  i   +    + [p. 238]    i 0 = x   i 0. = g i  i Q i g i ,  i g i