Could anybody tell me what this problem talks about?

Question

I found it in the section on sequence spaces. I don't know Russian.

Две последовательности $\{a_n\}$ и $\{b_n\}$ называем существенно различными, если $a_n\ne b_n$ для бесконечного множества натуральных чисел. Каждая конечная система существенно различных подпоследовательностей последовательности простых чисел образует линейно независимую систему.

Answer 1

Here is the translation to the best of my understanding:

Two sequences $\{a_n\}$ and $\{b_n\}$ are called essentially different if $a_n \not= b_n$ for infinitely many natural numbers. Each finite system of essentially different subsequences of the sequence of prime numbers forms linearly independent system.