MathOverflow

A result of Linton and Paré [1] states that (in ZFC), for comonad $D$ on the category $\mathbf{Set}$, the functor $D\text{-Coalg}^{\text{op}} \xrightarrow{U^\text{op}} \text{Set}^{\text{op}} \xrightarrow{2^{(-)}} \text{Set}$ is monadic. In other words...

On the Asymptotic Growth Rate of $G(N)$ in Ternary Goldbach Representations
I am investigating a structural refinement of the ternary Goldbach problem, focusing on how closely clustered the three primes in a representation $N = p + q + r$ can be, and what the optimal growth rate is for their maximum difference....

The following relates to what is known as the Lebesgue inequality, which gives an error bound for approximating functions under certain linear mappings, and ways to generalize that inequality.
Let $X$ be a normed linear space and let $Y$ be a subspace of $X$ with a best approximation in norm from that subset to every function in $X$ (e.g., $Y$ is a finite-dimensional linear subspace of $X$). Let $L:X\to Y$ be a bounded and idempotent linear...

Does anyone know of an early published reference for the (very easy) fact that all finite posets can be represented as the poset of divisibility of a finite set of integers?
Page 1 of Birkhoff's Lattice Theory (1940) talks about the poset of divisibility of all positive integers, and I assume this must have been known to Birkhoff, but I can't find this specific fact in his book....