$\mathbb{N}$-polyregular

$\mathbb{N}$-polyregular
$\mathbb{N}$-polyregular functions arise from well-quasi-orderings

A fundamental construction in formal language theory is the Myhill-Nerode congruence on words, whose finitedness characterizes regular language. This construction was generalized to functions from $Σ^*$ to $mathbb{Z}$ by Colcombet, Douéneau-Tabot, and Lopez to characterize the class of so-called $ma…