pub fn linearized_coeffs(eq_mix: &[Block128]) -> Vec<Flat<Block128>>
μ_j with Σ_u eq(r'',u)·bit_u(x) = Σ_j μ_j x^{2^j} for every x, bits in the tower basis.
μ_j
Σ_u eq(r'',u)·bit_u(x) = Σ_j μ_j x^{2^j}
x