# Flipping Boolean tag

**URL:** <https://forum.inductiveautomation.com/t/flipping-boolean-tag/93644>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [July 24, 2024, 4:13am UTC](https://forum.inductiveautomation.com/t/flipping-boolean-tag/93644 "2024-07-24T04:13:35Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [July 24, 2024, 2:36pm UTC](https://forum.inductiveautomation.com/t/flipping-boolean-tag/93644/5 "2024-07-24T14:36:53Z")

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> [@thomas\_wallace](#):
>
> ... switch a Boolean tag to always read the opposite of what it really is?

Is this related to your previous question, [Adding values together only if tag is true](https://forum.inductiveautomation.com/t/adding-values-together-only-if-tag-is-true/93640)?

The Expression Language has a built-in negation, `!`. The expression I gave would convert to,

```python
!{[default]Bool0} * {[default]Other0} +
!{[default]Bool1} * {[default]Other1} +
!{[default]Bool2} * {[default]Other2} +
... +
!{[default]Bool159} * {[default]Other159}

```

Python / Jython has the `not` operator.

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