Leanest quasi-orderings

Nachum Dershowitz*, E. Castedo Ellerman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A convenient method for defininga quasi-ordering, such as those used for proving termination of rewriting, is to choose the minimum of a set of quasi-orderings satisfying some desired traits. Unfortunately, a minimum in terms of set inclusion can be non-existent even when an intuitive "minimum" exists. We suggest an alternative to set inclusion, called "leanness", show that leanness is a partial order on quasi-orderings, and provide sufficient conditions for the existence of a "leanest" member of a set of total well-founded quasi-orderings.

Original languageEnglish
Pages (from-to)535-556
Number of pages22
JournalInformation and Computation
Issue number4
StatePublished - Apr 2007


  • Lexicographic path ordering
  • Quasi-ordering
  • Well-quasi-ordering


Dive into the research topics of 'Leanest quasi-orderings'. Together they form a unique fingerprint.

Cite this