name capture

Computing Dictionary

name capture definition

In beta reduction, when a term containing a free occurrence of a variable v is substituted into another term where v is bound the free v becomes spuriously bound or "captured". E.g.
(\ x . \ y . x y) y --> \ y . y y (WRONG)
This problem arises because two distinct variables have the same name. The most common solution is to rename the bound variable using alpha conversion:
(\ x . \ y' . x y') y --> \ y' . y y'
Another solution is to use de Bruijn notation.
Note that the argument expression, y, contained a free variable. The whole expression above must therefore be notionally contained within the body of some lambda abstraction which binds y. If we never reduce inside the body of a lambda abstraction (as in reduction to weak head normal form) then name capture cannot occur.

The Free On-line Dictionary of Computing, © Denis Howe 2010
Cite This Source
Previous Definition: name calling
Next Definition: name day
Words Near: name capture
More from
Synonyms and Antonyms for name capture
More from
Search for articles containing name capture
More from Translator Word FAQs presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature