  The aim of this work is to prove a technical result, that had been stated by
Boyallian, Kac and Liberati \cite{ck6}, on the degree of singular vectors of
finite Verma modules over the exceptional Lie superalgebra $E(1,6)$ that is
isomorphic to the annihilation superalgebra associated with the conformal
superalgebra $CK_{6}$.
