abstract algebra: show that an identity element does not exist with the definition

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Synergy: does the SSL certificate not exist?

I have installed Synergy v1.8.8 on my Ubuntu. It works well as a server until the next reboot. Once I restart the machine, it shows the following errors:

(2020-02-14T11:58:08) ERROR: ssl certificate doesn't exist: /.synergy/SSL/Synergy.pem

The only solution I found so far is to reinstall Synergy. Then it works fine (until the next reboot).

How can I fix it perfectly?

postgresql – Force the creation of a foreign key even if the reference does not exist

I have two tables foo Y bar, bar it has a column a what references foo.id as a foreign key When creating table bar prior to foo, the error column "a" referenced in foreign key constraint does not exist is given. This is obvious and intended. However, the creation of these two tables is handled by two different entities that I cannot control. It is guaranteed that no data will be added to any of the tables until both are successfully created, but the creation itself can occur out of order. Is there any way to force the creation of bar even if foo does not exist?

Play by mail: what online guides exist to help someone start a role play in the forum?

I'm not sure if this is the right exchange to ask and I'm not sure if the wording will be correct, but here it goes.

I am very fond of the role plays of the Post by Play forum where I can post every time I feel inspired, however, my partner says he had several negative experiences with them. As a gift from me for her, I was planning to start a role play in the forum where our world would be so she felt she could contribute and fix things that would otherwise bother her.

The scenario itself is a fantasy scenario that focuses on exploration with a small system similar to that of rolling so that the shoes are buckled to simulate the progress of the character (lacking such a thing has always been one of the biggest problems for me in most places).

Now, although I have some experience playing in role-playing forums with a unified configuration, my experience is very limited when it comes to the administrative department.

As for what I want to ask (and I'm sorry for what seems to be a rant. I just wanted to clarify what kind of experience I have with the role-playing games of the forum, what I have in mind and for what purpose I am creating this.) I have a great need for sources that I can read to prepare an inclusive environment that does not feel toxic or too restrictive, so I would like to know where I can read about sources that may be helpful to me.

c #: divide two elements separated by commas, if they exist

This method divides two elements separated by commas, if they exist, and increases the quantity if they are already in the list; otherwise, add the item to the list

I want to know if this code can be optimized a bit more. Any suggestions?

The following method works 100% well, but I feel it is not well done.

private void SeperateJoinedDisposables(IEnumerable joinedDisposables)
    if (!joinedDisposables.Any())

    foreach (var item in joinedDisposables.ToList())
        var amount = item.Amount;
        var container = item.Container;

        var disposable1 = container.Substring(0, container.IndexOf(","));
        var disposable2 = container.Substring(container.IndexOf(",") + 1);


        var disposableCointians1 = DisposablesModel.Containers.FirstOrDefault(x => x.Container.ToUpper().Contains(disposable1.ToUpper()));
        var disposableCointians2 = DisposablesModel.Containers.FirstOrDefault(x => x.Container.ToUpper().Contains(disposable2.ToUpper()));

        if (disposableCointians1 != null)
            disposableCointians1.Amount = (int.Parse(disposableCointians1.Amount) + int.Parse(amount)).ToString();
            DisposablesModel.Containers.Add(new Models.Container { Amount = amount, Container = disposable1 });

        if (disposableCointians2 != null)
            disposableCointians2.Amount = (int.Parse(disposableCointians2.Amount) + int.Parse(amount)).ToString();
            DisposablesModel.Containers.Add(new Models.Container { Amount = amount, Container = disposable2 });

Cart with laravel, Property error [product_id] does not exist on this collection instance

I made a webapp in Laravel and I am trying to make a view for the user with the summary of the order, where a list appears with the products that I add to the cart, the user data and the chosen delivery point. The issue is that when I want to show the cart data I get this error "Property [product_id] does not exist on this collection instance".
The other variables are good for me, I already tried them. The data is stored in a database, in the cart table that has a forgein key to link the products … I upload capture of the controller to which I put summary and view



here I add a capture of what would be the method in the controller of the arrito that I used to show in the cart view, the elements

cart controller

I hope you can help me, regards and thanks

Magento Eav Model Attribute Data Datetime class does not exist after Magento2 migration

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mediawiki – How to delete an indexed page that does not exist?

I contribute to a MediaWiki where I created a page with a link that begins with a slash. I corrected it a few years ago and it still shows in searches:

Page title matches
/BitmapLaserEngraving Bitmap engraving on the laser cutter
... tried to reproduce the bitmap engraving on display at MakeSpace, which the creator no longer remembered. I used

Clicking on the page takes me to a non-existent external link /BitmapLaserEngraving.

Wanted pages It lists the pages that are linked and that do not exist. This page has no link to indicate it, so I suspect it is a problem with indexing. I couldn't find how to do this on the special pages. Some other contributors to the wiki are nervous about rebuilding the index, as they say that sometimes things go wrong.

How can I solve this and what are the administrator rights that I should request?

magento2.3.3 – The website extracts from style-l.css that does not exist

After upgrading to Magento 2.3.3 on Windows and succeeding, I tried to change some CSS, but I discovered that while my code is generated, the old code overwrites it and it no longer exists. The inspection I made of the page revealed that this anomalous code is being extracted from style-l.css in:


This file does not exist.

The en_NZ folder doesn't really have a CSS folder anymore. Before, before the update, it was part of my method to show my changes to the website. But he doesn't do it anymore.

Does anyone have any clue as to what is going on?

How to enable Huawei Health app options for iOS that exist for Android?

I bought a Huawei Band 3 Pro a few months ago, and while using it with my Android phone, everything I needed was working (using the Huawei Health Android app).

But lately, I switched to an iPhone 11 pro and, therefore, I used the iOS version of that application. And it seems that the iOS application lacks several aspects. But maybe I just didn't find the right place to set it up correctly.

What I lack:

  • With Android, I could enable "notifications" that go to the band by source. Meaning: First I would enable notifications in general, and then I could select "I want calendar events and phone calls, but I don't want Facebook or WhatsApp." With iOS: I only found "notifications" that can be enabled. And now I receive calendar events, phone calls, facebook, whatsapp … just a lot of things that I really don't want to be notified. Question: Is there a way to configure individual sources for notifications?
  • Beyond that, the band knows several forms of exercises. Like indoor cycling. Which … Huawei's health app doesn't show me anything. With Android, I could see past workouts, for everybody The exercises offered by the band. With iOS, there are only steps, beats, sleep … and 3 outdoor activities (based on GPS). Question: Is there any way to access these "missing" activities, such as training data for indoor cycling?