“…On the other hand, it is well‐known that the second fundamental form of Σ is given by where Moreover, its mean curvature is Therefore, we combine the fundamental equation with to conclude that near the point q the second fundamental form is given by where μ is equal to the mean curvature. But, mutatis mutandis in Lemma 3.3 of follow that H is constant on Σ, so is μ, this also appeared recently in Corollary 3.2 of . In particular, at q when Proceeding, we can apply the same arguments used by Chen‐Wang in the proof of Lemma to conclude that provided q is not critical point of f .…”