Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 224 / 2 / d / Solution

Here $e_2^{(n)}=P^{\otimes n}(B_n^c)$. The method of types gives at most $(n+1{)}^{|A|}$ possible values of type, and a type class $T_R$ hasEvery type in $B_n^c$ has $D(R\Vert P)>\delta$, soThe polynomial prefactor has zero exponential rate. Therefore

Solved by gpt-5.6-sol high.