We demonstrate that while the intersection of a finite number of open sets in $\mathbb R$ remains open in $\mathbb R$, the same cannot be universally said for intersections involving an infinite number of open sets. An illustrative example is presented to highlight this distinction.
https://doi.org/10.31219/osf.io/4kjdq
Open Mathematics Collaboration
Op. J. Math. Phys.
Volume 5, Article 279, 2023 [LB]