Solution
= Solution
For arithmetic functions $f,g$ bounded in modulus by one, their <pretentious distance> up to $x$ is defined by
$$
\mathbb D(f,g;x)^2
=\sum_{p\leq x}\frac{1-\Re(f(p)\overline{g(p)})}{p}.
$$
= Solution
For arithmetic functions $f,g$ bounded in modulus by one, their <pretentious distance> up to $x$ is defined by
$$
\mathbb D(f,g;x)^2
=\sum_{p\leq x}\frac{1-\Re(f(p)\overline{g(p)})}{p}.
$$