Leanest Quasi-orderings Preliminary Version

نویسندگان

  • Nachum Dershowitz
  • E. Castedo Ellerman
چکیده

A convenient method for defining a 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 ordering of quasi-orderings, and provide sufficient conditions for the existence of a “leanest” ordering.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Leanest Quasi-orderings

A convenient method for defining a 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 parti...

متن کامل

On Fraisse's Order Type Conjecture

ing from the embeddability relation between order types, define a quasi-order to be a reflexive, transitive relation. Throughout this paper, the letters Q and R will range over quasi-ordered sets and classes. Various quasi-ordered spaces will be defined; in each case we will use the symbol < (perhaps with subscripts) to denote the quasi-order under consideration. If q1, q2 E Q, write ql < q2 to...

متن کامل

Intersection Quasi-Orderings: An Alternative Proof

This note provides an alternative proof of a known result on the existence of collections of orderings generating intersection quasi-orderings. Instead of proving the result from first principles, it is illustrated how it can be obtained by making use of an analogous relationship between partial orders and linear orders. Journal of Economic Literature Classification Nos.: C60, D11, D71. ∗ I tha...

متن کامل

Better Quasi-Ordered Transition Systems

Many existing algorithms for model checking of infinite-state systems operate on constraints which are used to represent (potentially infinite) sets of states. A general powerful technique which can be employed for proving termination of these algorithms is that of well quasi-orderings. Several methodologies have been proposed for derivation of new well quasi-ordered constraint systems. However...

متن کامل

! 2 -well Quasi-orderings in Reachability Analysis

The usefulness of well quasi-orderings for some aspects of veriication of innnite-state systems was already recognized by some researchers. This note shows that a ner notion, namely that of ! 2-well quasi-ordering, is the appropriate one for enlightening a particular problem related to termination of a reachabil-ity algorithm; the problem has already been touched on by Abdulla, Jonsson (1998). ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005