# Questions that look like definitions?

Generally, I do not ask question about exercises or homeworks. But the questions that I always would like to ask are of the form:

• How to show this?
• What does this mean?
• Is this property true?
• Why the authors of this paper assume this?
• $\dotsc$

I would like to know if this kind of questions are allowed here or not?

To make my self clear, let me give two examples here for the bullet 2 to 5:

• Here is one of my old question graph of a matrix
• The authors of this paper uses in Definition 2.1. the term principal block submatrix. Can anyone explain to me what this means?

For the first bullet, it is very often that I think about the question my self and I hesitate. So I cannot decide if I am true or not so I ask the question "How to show this?" (it is most likely I have the answer with me).

I hope you understand my question.

Thank you for your time. I appreciate your helps.

• I don't understand at all why you're worried these questions aren't on-topic. – Jack M Apr 11 '14 at 23:20
• Because I want to be sure that I get answers. – zighalo Apr 12 '14 at 2:33
• There is no way to be sure you get answers. – Gerry Myerson Apr 12 '14 at 7:59
• Thank you for your help and sorry for the question. – zighalo Apr 12 '14 at 9:01
• If you want more attention, you could set a bounty on the question – TrueDefault Apr 13 '14 at 1:20

I'm appreciative of Questions that identify the need for a definition, rather than charging ahead with an exercise that uses an unfamiliar term or phrase.

It is still desirable for users to research the problem definition before asking, so that Readers can respond in context to what the OP's difficulty entails. In that sense asking about or for a definition could potentially be off-topic, but only in the same way other "pass-through" (undigested) problem statements can be off-topic.

On that criterion I'd say you let your Readers down in the "old question" you mentioned. A brief search within the book you mention there found this definition, with a clear connection to the adjacency matrix that you bring up in the Question.