What is the meaning of q $\equiv 1\pmod p$?
If I were to write this as a definition, how would I explain with this means?
What is the meaning of q $\equiv 1\pmod p$?
If I were to write this as a definition, how would I explain with this means?
The meaning is that $p$ divides $q$ with remainder $1$.
Maybe the simplest way to phrase it would be:
If you subtract 1 from q, you get a multiple of p.
It means $p$ divides $q-1$.
$$q \equiv 1 \mod p$$
$$\implies q-1 \equiv 0 \mod p$$
$$\implies p | (q-1) $$