A Sum Theorem for (FPV) Operators and Normal Cones

On [3, p. 199] one says "We mention parenthetically that the proof of [99, Lemma 41.3] is incorrect, and we do not know whether it, [99, Theorem 41.5] and [99, Theorem 41.6] are true". The previously cited reference [99] is our reference [2]. The aim of this short note is to provide a result that improves upon [2, Lemma 41. 3]