1) No, there are no inverses for non-identity morphisms.
2) \\(\mathcal{C}\\): Yes, \\(s^{-1}=s,\mathrm{id}_z^{-1}=\mathrm{id}_z\\). \\(\mathcal{D}\\): No, there are no inverses for non-identity morphisms.
2) \\(\mathcal{C}\\): Yes, \\(s^{-1}=s,\mathrm{id}_z^{-1}=\mathrm{id}_z\\). \\(\mathcal{D}\\): No, there are no inverses for non-identity morphisms.
Version 2.1.8p2
