Groups of Class Transpositions with Prescribed Prime Divisors of the Moduli

For a set $\mathcal P$ of odd primes, let $\operatorname{CT}_{\mathcal P}(\mathbb{Z})$ denote the group generated by all class transpositions whose moduli have no odd prime divisors outside $\mathcal P$. We prove that \[ \bigl\langle \operatorname{CT}_{\mathcal P_1}(\mathbb{Z}),\operatorname{CT}_{\m