(I am experimenting with writing arrows backwards.)
Let $R$ denote a commutative ring. Is there a term for those sequences $A : \mathcal{P}(R) \leftarrow \mathbb{N}$ satisfying the following requirements resembling the definition of a graded ring?
- $A_i A_j \subseteq A_{i+j}$ and $1 \in A_0$
- $A_i + A_i \subseteq A_i$ and $0 \in A_i$
- $RA_i \subseteq A_i$
Example. Let $R = \mathbb{Z},$ $A_0 = \mathbb{Z}$, and $A_i = 2\mathbb{Z}$ for all $i>0$.
Motivation.
If a sequence $A$ into $\mathcal{P}(R)$ satisfies these conditions, then the following subset of the polynomial algebra $R[x]$ is in fact an $R$-subalgebra:
$$\bigcup_{n \in \mathbb{N}}\sum_{i < n}A_i x^i$$
2 and 3 ensures that the $A_i$'s are (left) ideals of $R$, and 1 that $A_0 = R$. Such a sequence is called a filtration of the unital ring $R$ by (left) ideals. More generally, you have the notion of filtration of an (left) $R$-module by a sequence of $R$-submodules. Endowed with such a filtration, your object is called a filtered ring or filtered module. If this filtration has some monotonicity property (like being increasing or decreasing) you can define a graded object (ring or module) associated to the filtered object.