Coloring linear orders with Rado's partial order

Let R be the preorder of embeddability between countable linear orders colored with elements of Rado’s partial order (a standard example of a wqo which is not a bqo). We show that R has fairly high complexity with respect to Borel reducibility (e.g. if P is a Borel preorder then P ≤B R), although its exact classification remains open.

• Type: Journal
• Year: 2007
• Where: MLQ
• Authors: Riccardo Camerlo, Alberto Marcone
• Keywords: Countable Linear Orders, MLQ 2007, Rado’s Partial Order, Standard Example