Addendum: Conformal deformation of a Riemannian metric to a scalar flat metric with constant mean curvature (Q1334330)

In the author's paper [ibid. 136, No. 1, 1-50 (1992; Zbl 0766.53033)] the first eigenvalue \(\lambda_1(B)\) of the problem \[ \begin{cases} Lf=0 & \text{on \(M\),}\\ Bf+\lambda_1(B)f=0 & \text{on \(\partial M\),}\end{cases} \] where \((L,B)\) is the conformal Laplacian, was considered, under the tacit assumption that \(\lambda_1(B)\) is finite. This addendum discusses this question in detail; it is remarked that only Theorem 2 and Propositions 1.4 and 1.5 in above paper need the assumption on finiteness of \(\lambda_1(B)\) whereas the other statements remain correct without this explicit assumption.