On quasi ordinal diagram systems

Mitsuhiro Okada, Yuta Takahashi

Research output: Contribution to journalConference articlepeer-review


The purposes of this note are the following two; we first generalize Okada-Takeuti’s well quasi ordinal diagram theory, utilizing the recent result of Dershowitz-Tzameret’s version of tree embedding theorem with gap conditions. Second, we discuss possible use of such strong ordinal notation systems for the purpose of a typical traditional termination proof method for term rewriting systems, especially for second-order (pattern-matching-based) rewriting systems including a rewrite-theoretic version of Buchholz’s hydra game.

Original languageEnglish
Pages (from-to)38-49
Number of pages12
JournalElectronic Proceedings in Theoretical Computer Science, EPTCS
Publication statusPublished - 2019
Event10th International Workshop on Computing with Terms and Graphs, TERMGRAPH 2018 - Oxford, United Kingdom
Duration: 2018 Jul 72018 Jul 7

ASJC Scopus subject areas

  • Software


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