  We compare the reduced void probability function (VPF) inside and outside of
cosmic voids in the TNG300-1 simulation, both in real and simulated redshift
space. The VPF is a special case of the counts-in-cells approach for extracting
information of high-order clustering that is crucial for a full understanding
of the distribution of galaxies. Previous studies have validated the
hierarchical scaling paradigm of galaxy clustering moments, in good agreement
with the "negative binomial" model, in redshift surveys, but have also reported
that this paradigm is not valid in real space. However, in this work we find
that hierarchical scaling can indeed be found in real space inside cosmic
voids. This is well fitted by the negative binomial model. We find this result
to be robust against changes in void identification, galaxy mass, random
dilutions, and redshift. We also obtain that the VPF in real space at high
redshift approaches the negative binomial model, and therefore it is similar to
the VPF inside voids at the present time. This study points, for the first
time, towards evidence of hierarchical scaling of high-order clustering of
galaxies in real space inside voids, preserving the pristine structure
formation processes of the Universe.
