additive relation造句

So there are situations where the additive relations ( constant difference and constant sum ) are correct and other situations where the multiplicative relations ( constant ratio and constant product ) are correct.
That is, we can combine in a side-by-side fashion lengths of rigid steel rods, for example, such that the additive relations between lengths is readily observed.
It's difficult to find additive relation in a sentence. 用additive relation造句挺难的