# Using \`format/2\` with attributed variable on a pengine

**URL:** <https://swi-prolog.discourse.group/t/using-format-2-with-attributed-variable-on-a-pengine/6996>\
**Category:** Help!\
**Created:** [November 23, 2023, 8:12pm UTC](https://swi-prolog.discourse.group/t/using-format-2-with-attributed-variable-on-a-pengine/6996 "2023-11-23T20:12:23Z")\
**Posts on this page:** 1\
**Showing post:** 27

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**Author:** ![ridgeworks](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/ridgeworks/32/886_2.png) [@ridgeworks](https://swi-prolog.discourse.group/u/ridgeworks)\
**Post date:** [December 7, 2023, 8:42pm UTC](https://swi-prolog.discourse.group/t/using-format-2-with-attributed-variable-on-a-pengine/6996/27 "2023-12-07T20:42:31Z")

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Got stuck so opened a new topic:

> [@Use of \`attribute\_goals//1\` to compose answers](https://swi-prolog.discourse.group/t/use-of-attribute-goals-1-to-compose-answers/7045):
>
> Apologies on the length of this post but think I need to provide some motivation. Background: Attributed variables are a core feature supporting many (most?) CLP dialects on Prolog. By permitting logic variables to be “annotated”, they effectively permit constraint networks to be constructed without requiring a separately managed constraint store, really a brilliant idea IMHO. The constraint networks built using attributed variables are terms which are typically cyclic (they’re graphs) and can…

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