The undefined variables ℕ and 𝕊ᶻ

[zxm403089989]

I try to test the examples on Fermi Hubbard model and Heisenberg model described in document, however both of them return:

UndefVarError: `ℕ` not defined

and

UndefVarError: `𝕊ᶻ` not defined

How to solve this?

[waltergu]

ExactDiagonalization@0.2.0 solves this problem.