Let $(\mathcal{A},\otimes,1_{\mathcal{A}})$ be a monoidal category, and let $M$ be a rigid object of $M$, with left and right dual respectively denoted by $$ \Big\{M^*,~~~ \epsilon_l:M^* \otimes M \to 1_{\mathcal{A}},~~~ \eta_l:1_{\mathcal{A}} \to M \otimes M^*\Big\} $$ and $$ \Big\{{}^*M, ~~~\epsilon_r: M \otimes {}^*M \to 1_{\mathcal{A}},~~~\eta_r: 1_{\mathcal{A}} \to {}^*M \otimes M\Big\} $$ respectively (just as in Wikipedia $\epsilon$ denotes evaluation and $\eta$ the coevaluation). Let's assume that we have isomorphisms $f_l:M \to M^*$ and $f_r:M \to {}^*M$. Then do we have the identity $$ (\mathrm{id} \otimes f_l^{-1}) \circ \eta_l(1_{\mathcal{A}}) = (f_r^{-1} \otimes \mathrm{id}) \circ \eta_r(1_{\mathcal{A}})? $$ This works for finite dimensional vector spaces, so I have guessed that it works in general. Also, do we have the identities $$ (f_l \otimes \mathrm{id}) \circ \epsilon_l = (\mathrm{id} \otimes f_r) \circ \epsilon_r: M \otimes M \to 1_{\mathcal{A}}? $$