terminal constraint for z_T, time step consistency between z_t and s_t (consistency on t)

[smilesun]

In the previous verion of implementation

tube_mpc/tmpc/constraint_tightening_z_terminal.py

Line 19 in 4bf8d21

&M[(A+BK^z)z_{t-1} + s_t]<=1

, from commit 4bf8d21

we did not consider z_t and s_t, but z_{t-1} and s_t, and we consider the worst case of $s$, so $s$ will not depend on time, is it necessiary to put z_{t-1}, s_{t-1} together for computation of positive invariant set?