The reverse mathematics of Hindman's theorem for sums of exactly two elements

Barbara F. Csima, Damir D. Dzhafarov, Denis R. Hirschfeldt +3

Hindman's Theorem (HT) states that for every coloring of $\mathbb{N}$ with finitely many colors, there is an infinite set $H\subseteq \mathbb{N}$ such that all nonempty sums of dist…