Algebraic properties of overflow semirings

We introduce the overflow semiring $S=A{\uplus }_{\text{ord}}L$, extending a positive information algebra $A$ by a join-semilattice $L$, where elements of $L$ dominate $A$ and arithmetic in $L$ reduces to the join. This models some kind of overflow in computational systems and generalizes the transition from finite to infinite cardinal arithmetic. We characterize the idempotent elements of $S$ and $S[X]$, fully classify idempotent power series over cardinal numbers, describe the structure of prime and maximal ideals, compute the Krull dimension of $S$ ($\dim S=\dim A+\mathrm{\mid }L\mathrm{\mid }$ for well-ordered finite $L$), and establish Noetherian and Artinian criteria.