CR-submanifold formal-equivalence conjecture of Baouendi, Rothschild, and Zaitsev

Let $M\subset\mathbb C^N$ be a real analytic CR submanifold. Let $p\in M$, let $M'\subset\mathbb C^N$ be a real analytic submanifold with $\dim_{\mathbb R}M=\dim_{\mathbb R}M'$, and let $p'\in M'$. Let $F:(\mathbb C^N,p)\to(\mathbb C^N,p')$ be a formal invertible mapping sending $M$ into $M'$. Baouendi–Rothschild–Zaitsev CR-submanifold conjecture. The mapping $F$ can be approximated by holomorphic mappings as in the conclusion of the approximation theorem. This would reduce the exceptional locus to the points where the source is not CR, addressing formal equivalence versus local biholomorphic equivalence.