\node (point) at (0, 0) {$\color{red}{\bullet}$}; \node (line0) at (2, 1) {$\color{blue}{\bullet}_0$}; \node (line1) at (2, -1) {$\color{red}{\bullet}_1$}; \draw (line0) -- (line1) node[midway] (linemid) {}; ; \draw[->] (point) to[out=-70,in=180] node[midway] (a) {$\delta^1$} (line1); \node (sq00) at (4, -1) {$\color{red}\bullet_{01}$}; \node (sq01) at (4, 1) {$\color{blue}{\bullet}_{00}$}; \node (sq10) at (6, -1) {$\bullet_{11}$}; \node (sq11) at (6, 1) {$\bullet_{10}$}; \draw (sq00) -- node[midway] (linemid_img) {} (sq01) -- (sq11) -- (sq10) -- (sq00); \draw[->] (linemid) -- node[midway] (b) {$\delta^0_0$} (linemid_img);