## simplifying expressions – Strategy tips for time consuming FullSimplify, crashing FullSimplify, and strange behavior of TimeConstraint

I am trying to simplify a complicated integration result containing both error functions and MeijerG – I give the full expression below. A simple FullSimplify(expression,{x>0,y>0,z>0}) would run for about one day and then simply crash the kernel without returning any result. I have been trying to play around with the TimeConstraint parameter. I started multiple runs at the same time, with TimeConstraint->{10000n,10000n} for n=1,5,9.

Weirdly, the one for n=9 which should have run the longest already finished after just a few minutes without significant simplification and the warning message (note the negative sign!)

“FullSimplify::time: Time spent on a transformation exceeded -2.95596
10^12 seconds, and the transformation was aborted. Increasing the
value of TimeConstraint option may improve the result of
simplification.”

The one for n=1 crashed after a few minutes without result. The one for n=5 is still running.

Any guesses what causes this erratic behavior? What is the best way to use TimeConstraint (specifically, what is the best ration between the local and total time parameter)?

And what is the best strategy to find out if a result like this can be further simplified?
I did a regular Simplify first, of course. I guess I could split the expression into separate terms, but my suspicion is that some of them only yield a simpler expression when taken together with the other terms.

Would be happy for any ideas.

Here is the function (where I know that x, y, z are positive reals):

``````((x*Erf(2*x*z - y*z)*((2*Pi*(x - y)*(E^(2*x^2)*(-1 + Sqrt(2*Pi)*x)*(3*x - y)
+ Pi*x*(1 - 6*x^2 + 2*x*y)*Erfi(Sqrt(2)*x)
+ x*(-1 + 6*x^2 - 2*x*y)*ExpIntegralEi(2*x^2)))/E^(2*x^2)
- MeijerG({{0, 1/2}, {}}, {{1/2, 1, 1}, {}}, 2*x^2)
+ 2*((x - y)^2*MeijerG({{0, 1/2, 1}, {}}, {{1/2, 1}, {}}, -(1/(Sqrt(2)*x)), 1/2)
+ x*(-2*(x - y)*MeijerG({{1/2, 1, 1}, {}}, {{1, 3/2}, {}}, -(1/(Sqrt(2)*x)), 1/2)
+ x*MeijerG({{1, 1, 3/2}, {}}, {{3/2, 2}, {}}, -(1/(Sqrt(2)*x)), 1/2)))))/E^(2*(x - y)^2)
- (x*Erf((2*x + y)*z)*((2*Pi*(x + y)*(E^(2*x^2)*(-1 + Sqrt(2*Pi)*x)*(3*x + y)
+ Pi*x*(1 - 6*x^2 - 2*x*y)*Erfi(Sqrt(2)*x)
+ x*(-1 + 6*x^2 + 2*x*y)*ExpIntegralEi(2*x^2)))/E^(2*x^2)
- MeijerG({{0, 1/2}, {}}, {{1/2, 1, 1}, {}}, 2*x^2)
+ 2*((x + y)^2*MeijerG({{0, 1/2, 1}, {}}, {{1/2, 1}, {}}, -(1/(Sqrt(2)*x)), 1/2)
+ x*(-2*(x + y)*MeijerG({{1/2, 1, 1}, {}}, {{1, 3/2}, {}}, -(1/(Sqrt(2)*x)), 1/2)
+ x*MeijerG({{1, 1, 3/2}, {}}, {{3/2, 2}, {}}, -(1/(Sqrt(2)*x)), 1/2)))))/E^(2*(x + y)^2))/(2*Pi*x^2)
``````

## DateBounds gives strange results

In v12.3.1, this code

``````DateBounds[
{DateObject[{2013, 1, 1, 1, 0, 0.}, "Instant", "Gregorian", 1.]},
"Year"]
``````

gives

which seems wrong.

Can this be considered as a bug?

And just out of curiosity, what’s the possible cause for such result?

## macos – iCloud strange error does not sync

With iCloud Desktop & Download folder sync, and it started synching to my 2nd Mac, but then it said it was full, so I paid to be on the 50Gb plan. Once I enabled the 50Gb of space, an error message immediately appeared that said something like “The Mac system is not able to sync right now”. Why did this message appear? My internet connect is robust, both ethernet/wifi. My credit card was not rejected it was accepted and in the system settings it shows I now have the upgraded storage. When I had only 5Gb of free iCloud storage, the sync worked OK for the “Desktop & Downloads” setting. How can I retrive this error message from the system log? What caused this error?

## linux – Strange problem with printing Memo documents on Samsung phone and moving to Ubuntu PC

I have been backing up Memo documents on my Samsung Galaxy 5 to my PC by printing the Memo documents to PDF on the phone and then moving them to my PC. My PC has Ubuntu version 20.04.2 LTS.

This worked fine for a while but now for some reason the Memo documents are not printing to PDF, instead creating blank PDF files with no text. Sometimes the Memo documents do print to PDF on the phone but appear as blank documents when opened in the Files window for the Samsung phone on my PC desktop. Some of the Memo documents do print successfully on both the phone as well as the PC, so the problem is not consistent. Just before this began happening, I got a message on the Samsung in Memo saying “Sorry the print spooler has stopped”, whatever that means.

## Strange opera mini ad – is it Pegasus (spyware)?

Resently, When using opramini, you are constantly faced with an ad.

This is very strange and suspicious. Because advertising is the operamini itself.

What the hell is it!?

## lighting – Unreal 4 – Static mesh has strange, glitchy shadows?

The first image below shows my mesh in Blender with the Blender lighting, and the second image from inside UE4 has this weird shading on it. Is there any way to help it look like the first image? I’ve tried two-sided lighting, increasing the lightmap resolution, nothing seems to fix it. If anybody knows a fix, please let me know. Thanks! :]

## Strange Variations of URL Showing Up in Google Search Console

Was the website hacked?

Most certainly so.
Anyway there is probably no good reason to take time to assess so and how much, as soon as you find content that shouldn’t be there (as you say if I understand right that the pages do return content, what you call gibberish is Javascript code which, like any tool, could be used for good and bad reasons, it can be there as well for analytics for example as a quick view on it might conclude, but then the console shows various resources are tried all over the place including external to your website with only errors, which is more a sign of a malware of some sort than some clean analytics system), there is only one sane and safe option:
re-install your website completely from scratch from some known sane backup of it (you do have backups?)

Do not attempt to “clean” things by looking at each existing file one by one because you can miss a lot of things that way

If you can, you should shut it down immediately, and then clean it. Otherwise it may be currently being used in some attacks.

What can I do to fix this problem and prevent it from happening?

This is difficult to reply in general, you should consult your current webhosting company and discuss this with them. It typically means increasing security, which also starts on your end, by changing any password you have to access the site in “admin” mode (like credentials to do FTP uploads, or credentials to open the hosting company panel, etc.) to make sure it is both good, unique and never stored in plain text.

It also depends how your website is constructed. If you used a CMS like WordPress you can be hacked through plugins you installed, so you have to review all of that.

Some companies can sell you services to either clean your current site and/or review its security to defend against further attacks. It is probably difficult to guarantee any efficiency here.

Do I just submit a new request to remove these strange URLS in Google Search Console?

Maybe, but if you don’t clean your website the problem will re-appear. If Google knows about those URLs it is because they appear “somewhere”, there is some content linking to them, as it typically happens with any malware that hosts content all over the place (aka: in multiple websites to combat detection)

## plugins – Strange footer – pswp__top-bar problem

plugins – Strange footer – pswp__top-bar problem – WordPress Development Stack Exchange