Martin's Axiom, Large Continuum and Global $Σ^1_n$-Uniformization

Abstract

We construct a generic extension of $L$ satisfying Martin's Axiom, $2^{\aleph_0}=\aleph_3$, a lightface $Δ^1_3$ wellorder of the reals, and $Σ^1_n$-uniformization for every $n\geq 2$ simultaneously.