This question may well become a candidate for deletion, given that another question has also been asked before that also has the same code fragments if I am not mistaken. 
May or may not go for deletion, you don't know with the moderator just doing whatever.
Note : probably it is not going to be deleted if the moderator addresses the question ?

@Carl Love 

By the looks of it, the Mapleprimes forum software is ‘lagging behind’ the current modern forum software. 
A ridiculous thing in itself, Maplesoft, a renowned company that wants its users to get on well with their software, does not create the conditions for this learning process, but instead fills Maple users with outdated forum software to learn to use Maple better.

This gives a moderator the opportunity to simply delete misplaced questions by a Maple user that do relate to topic , at will.
Unfortunately, there is no consistent approach from the moderator who should start deleting these misplaced questions.
Sometimes questions may or may not be removed and this creates confusion among the questioners and those answering the question.

I would put in big red letters above the forum: post questions related to the same topic together.

There are several moderators on the mapleprimes forum, so I would say delete wrongly asked questions immediately. 
Also now the forum shows a question related to previous questions on the forum , but posted separately by a user: this is a wrong attitude
Now if you as moderator(s) are so keen to remove wrong questions , do it consistently , if not , find something else to bother someone.

Bring this question under another question : How define D-operator (bilinear hirota derivative) for PDEs?

@salim-barzani 

How-Find-Bilinear-Form-For-Of-BLequation
This new question you must add to the already existing question here 
Adding or branching..

This standalone new question will probably yes or no deleted ?
note:  this new question is not the same as last one recently removed , its looks on a earlier question
So: keep all question together, doubling or partly doubling doesn't matter , keep all question  together
if it falls onder the same topic

So bring your latest question here ....

@salim-barzani 
Lol .. keep related questions together anyway in a startquestion : following a row or as branch
You are sure you did the right procedure for adding a branch ?
A branch belongs by the question i think: i never used it 

This undermines the whole flow of investigation

@salim-barzani 
I understand, it is not consistent behaviour the moderator is showing, so is it yes or no ?
Had he moderator kept reminding you to do things differently with the question , you would have done the right thing I think.
The moderator also let it happen and didn't get on top of it to correct you and now just delete a question.
This does not deserve any beauty prize and the moderator could have put your wrong post under the existing question as an example and reminded you again of the correct procedure to ask questions.

This moderator falls short in didactic quality here

So add your deleted question /post  complete again here to this existing question row or as a branch of the existing question,then you fullfill to the rules

@salim-barzani 
yes, when it is the same topic closely related , its better to keep it here on the forum as a whole 
So , add again the complete ! deleted post  to the row of existing answers from How define D-operator (bilinear hirota derivative) for PDEs?
Or make a branche then from this new question 

@mmcdara 
"'m sorry but the font is too small and the text too fuzzy for me to see clearly what it's written" 
In this case you can zoom in /out with middle mouse scroll wheel,  to read better on the page on windows
But this is not the complete @removed post ..?

@mmcdara 

Where is the other most recent question about this topic ?
It seems to be deleted, by whom..
As user are removing their posts , when it is answered by a Maple specialist here on the forum, then it must not be deleted

@salim-barzani 
Is there now availability of two external Maple packages, which can support this search ?

@salim-barzani ,Whether there is a true pde specialist to be found here on the forum, who masters all the techniques to manipulate the pde's ?
If not, then there are forum members who are a specialist in the maple language and master it just fine, but are not aware of the techniques used with PDEs 
The only thing left then is to describe those desired techniques on the forum in the hope that a maple specialist can translate it into maple code.

But maple specialist help is much easier via chatGPT to get an idea of the techniques used with PDEs
I also read some of this way about the bilinear form of a pde, but this requires study of the topic and context. 

@salim-barzani , What makes@dharr not arrive now at the same result as in the document ?
I remember there was an issue before a while back , in which a result found still needed some ‘formula massage’, before it could be seen in the required format as the document read.

Give more details maybe someone can answer this?

Root two is an irrational number and you take this value for a
If you then assume that x is a real number. 
Then what will maple calculate for the function values ?

@scallopedpancake 
Setup screen ? in Physics package