shown in [Figure \[pic3\]]{}, the spin of sub[haloes]{} declines at low redshift. We have checked many more sub[haloes]{} not displayed in [Figure \[pic3\]]{} and we find that most of them display the same trend. We also plot a dashed line for a halo as reference. The halo is in the same mass range as those sub[haloes]{} selected. Its spin almost does not change at low redshift. This piece of evidence strongly supports the claim that sub[haloes]{} suffer from stripping, loosing their spin over time.

The information at the high redshift end in [Figure \[pic3\]]{} is not reliable since the progenitors don’t contain very many particles. This results in the large fluctuations seen here.

![The evolution of Peebles (upper) and Bullock (lower) spin of six selected sub[haloes]{} from BoxA. Sub[haloes]{} have at least 300 particles and are less massive than $10^9h^{-1}\rm M_{\odot}$. All selected sub[haloes]{} form prior to redshift 8. Solid colored lines represent different sub[haloes]{}. The black dashed line shows the spin of a halo changing with time as a reference.[]{data-label="pic3"}](LZ_Subfind_Peebles "fig:"){width="\linewidth"}\
![The evolution of Peebles (upper) and Bullock (lower) spin of six selected sub[haloes]{} from BoxA. Sub[haloes]{} have at least 300 particles and are less massive than $10^9h^{-1}\rm M_{\odot}$. 