I try to post question but I always get the message: This post does not meet our quality standards.
For example: I try to understand why by definition
$[c0,c1,...cn]=[c0,[c1,...cn]]$ and also
But not $[c0,c1,...cn]=[c0,c1,[c2,...cn]]$ for example.
P is a prime such that $q=p+2$ is also a prime.
I need to prove that there is an integer a such that $p|a^2-q$ if and only if there is b such that $q|b^2-p$.