# Why the answer contains a \`false\`?

**URL:** <https://swi-prolog.discourse.group/t/why-the-answer-contains-a-false/5425>\
**Category:** Predicate\
**Tags:** discussion, how-to\
**Created:** [May 24, 2022, 6:41pm UTC](https://swi-prolog.discourse.group/t/why-the-answer-contains-a-false/5425 "2022-05-24T18:41:11Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![brebs](https://avatars.discourse-cdn.com/v4/letter/b/e9c0ed/32.png) [@brebs](https://swi-prolog.discourse.group/u/brebs)\
**Post date:** [May 24, 2022, 7:00pm UTC](https://swi-prolog.discourse.group/t/why-the-answer-contains-a-false/5425/2 "2022-05-24T19:00:53Z")

</div>

Related: [How to find unexpected choicepoints?](https://swi-prolog.discourse.group/t/how-to-find-unexpected-choicepoints/2423)

Can prevent unwanted backtracking with:

```prolog
once(data(catalog1, mike, deposit, X)).

```

That `data_deposite_get/3` is probably useful, but not _necessary_.

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