4 problems

Let $X\subseteq\mathbb{C}$ be a connected open set and let $f:X\to\mathbb{C}$ be a meromorphic elementary function. A function is solvable when its equation with a constant right-h…

An elementary universal formula without integration is an elementary formula intended to achieve uniform approximation of continuous functions on $[0,1]$, without using integration…

Optimality conjecture. The formulas in Tables and are the best possible, in the Lehmer sense, $n$-term formulas for the respective sets of $n$ primes or Gaussian primes.

Elementary-integrability Skolem-set conjecture. The set $E_f$ is a Skolem set, that is, a union of finitely many arithmetic progressions. The source presents this as a proposed sta…