If we substitute in respectively,
and describe the resulting functions, respectively, with (U), (V), (W), then by u = (U), v = (V), w = (W) it is possible to comply with (1). [AU 1]
For example, we obtain for the first of them:
and this is fulfilled, because we have:
if there exist the following new equations:
- Due to the same order of all parts of equations (1), the right-hand sides of the substitution formulas (2) can be multiplied by a common factor, without changing the results.