“…At an intuitive level, the correspondence between φ 1 and φ 2 may be understood from the fact that the Verma modules, which they generate, coincide since the highest weights only depend upon (p (1) 0 ) 2 = (p (2) 0 ) 2 . The chiral family is built up [17,25,26,5,27] from the following operators is such that ψ j and ψ j are solutions of the equations [24,17] − d 2 ψ j (σ)…”