Connection between spin-singlet and hierarchical wave functions in the fractional quantum Hall effect

We propose trial expressions for the many-body wave functions of the incompressible fluid states responsible for the fractional quantum Hall effect at filling factor ν not equal to 1/m. For ν=q/p, the wave functions are related to the wave functions for the total $S=0$ states of objects with spin (q-1)2. In particular, for ν=2/5 the wave function is related to the total $S=0$, ν=1/2 hollow-core-model ground state recently discovered by Haldane and Rezayi.