# Weird behaviour on a simple project of an adder

**URL:** <https://circuitverse.discourse.group/t/weird-behaviour-on-a-simple-project-of-an-adder/32>\
**Category:** Bug reports\
**Created:** [October 18, 2026, 2:39pm UTC](https://circuitverse.discourse.group/t/weird-behaviour-on-a-simple-project-of-an-adder/32 "2026-10-18T14:39:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![VittorioScarano](https://yyz1.discourse-cdn.com/flex047/user_avatar/circuitverse.discourse.group/vittorioscarano/32/84_2.png) [@VittorioScarano](https://circuitverse.discourse.group/u/VittorioScarano)\
**Post date:** [October 18, 2026, 2:39pm UTC](https://circuitverse.discourse.group/t/weird-behaviour-on-a-simple-project-of-an-adder/32/1 "2026-10-18T14:39:29Z")

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Hi there. I am producing a simple project, but I find a weird behaviour. Started from scratch but it keeps showing it. It is a simple implementation of a Sum of Products canonical form for an adder. So, I need to have 3 inputs, put them (in true or negated form) into 4 AND and put together everything in an OR. While for the first 2 inputs (x1 and x2) everything works fine, for x3, it looks like the wire down is disconnected from a first point onward. Also deleted to redo it but it keeps showing. Also, moving the x2 bit, also affects weirdly the third line of x3.

Is there any suggestion for me to solve this problem? The project can be found at [CircuitVerse - Adder](https://circuitverse.org/users/425624/projects/2085825) and I thank in advance any suggestion.

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**Author:** ![VittorioScarano](https://yyz1.discourse-cdn.com/flex047/user_avatar/circuitverse.discourse.group/vittorioscarano/32/84_2.png) [@VittorioScarano](https://circuitverse.discourse.group/u/VittorioScarano)\
**Post date:** [October 18, 2026, 3:20pm UTC](https://circuitverse.discourse.group/t/weird-behaviour-on-a-simple-project-of-an-adder/32/2 "2026-10-18T15:20:43Z")

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Hi. Just a quick update. I completely redid from scratch. And now it worked. Not sure what it was. The correct project is at [CircuitVerse - Bit di somma per 3 bits](https://circuitverse.org/users/425624/projects/2085851)

Maybe I was too close with wires and found a bug