**Crossing factorization.** `U_{a,b} = U_{a+b,b}⁺ · J(P_{a+b}) · U_{a,a+b}⁻`, where `J` is the diagonal substitution and `P_{a+b} = eulerSer (-1) (a+b)`.

Initializing...

**Crossing factorization.** `U_{a,b} = U_{a+b,b}⁺ · J(P_{a+b}) · U_{a,a+b}⁻`, where `J` is the diagonal substitution and `P_{a+b} = eulerSer (-1) (a+b)`. · Prove2Me