“…The final result is much richer than in the "standard" conformal contact superalgebras K n where, up to duality, there is only one family of singular vectors, all of degree 1: we show that for A(K ′ 4 ) there are four families of singular vectors of degree 1, four families of singular vectors of degree 2 and two "exceptional" singular vectors of degree 3. Since the classification of singular vectors in finite Verma modules is equivalent to the classification of morphisms between such modules, we show that these morphisms can be arranged in an infinite number of bilateral complexes in a picture (see Figure 1) which is similar to those obtained for the exceptional linearly compact Lie superalgebras E(1, 6), E (3,6), E (3,8) and E(5, 10) (see [17,18,19,20,4,6]). In a subsequent publication we will compute the homology of these complexes and provide an explicit construction of all irreducible quotients.…”