I was reading something and have come across something not clear in terms of grammar. Here is the passage:
One may either (1) repeatedly observe two things always (or at least for the most part) together, or (2) one may sometimes observe them together and sometimes not together. If, as in the latter case, one only sometimes observes two things together after multiple observations, then the two things are just as likely to happen together as not.
I have three main questions here;
Firstly, as far as I understand, this bold part means that "then two things' happening together is as likely as not happening together" Is that what understood is correct?
The second one is related to structure. I think grammatically just here (just as likely to happen ...) is put for extra emphasis. Therefore here "just as" as a conjunction is not used; rather; "as...as" as a tool of comparison is used. Because the usage of "just as" is completely different. Is that correct?
The third one is related to structure as well. Simply put, If I want to say the bold part in an extended way, should I like this "then the two things are just as likely to happen together as they are not together", or like this "then the two things are just as likely to happen together as they don't happen together"? Which one is correct? If you have a different idea please say it as well?
I know It is a quite complicated question. But I really need help to understand it.