Well rewrite orderings and well quasi-orderings
Abstract
This paper studies well (quasi) orderings described as rewrite orderings and proposes a new family of well (quasi) orderings that extends the embedding or divisibility order of G. Higman. For instance, the well (quasi) orderings proposed in this paper may contain pairs of the form f(f(x)) > f(g(f(x))). Conditions under which the transitive closure of a well-founded rewrite relation is a well-quasi-rodering are given. Finally, an attempt to extend the recursive path ordering is proposed.