\begin{tikzcd}[column sep=small, row sep=small, nodes={font=\scriptsize}]
H^i(L) \arrow[r] \arrow[d, "\alpha"'] & H^i(G) \arrow[r] \arrow[d, "\beta"] & H^{i+1}(F) \arrow[r] \arrow[d, "\varphi"] & H^{i+1}(L) \arrow[r] \arrow[d, "\alpha'"] & H^{i+1}(G) \arrow[d, "\beta'"] \\
H^i(\hat{L}) \arrow[r] & H^i(\hat{G}) \arrow[r] & H^{i+1}(\hat{F}) \arrow[r] & H^{i+1}(\hat{L}) \arrow[r] & H^{i+1}(\hat{G})
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small, nodes={font=\scriptsize}]
\operatorname{Pic}(X) \arrow[r, "\text{injectif}"'] \arrow[rr, bend left=20] & \operatorname{Pic}(\hat{C}') \arrow[r] \arrow[dr] & \operatorname{Pic}(C') \arrow[r] & \operatorname{Pic}(\widetilde{C'}) \\
 & & \text{noyau} &
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small, nodes={font=\scriptsize}]
 & \mathbf{Z}\xi \arrow[r, no head] \arrow[d] & \mathbf{Z}\xi \arrow[d, "(?)"] & \\
0 \arrow[r] & \operatorname{Pic}(X) \arrow[r] & \operatorname{Pic}(\hat{C}') \arrow[d] & \\
 & \operatorname{Pic}(C) \arrow[r] & \operatorname{Pic}(C') \arrow[r] & \operatorname{Pic}(\widetilde{C'})
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small, nodes={font=\scriptsize}]
X \arrow[r, "i"] \arrow[d] & X' \arrow[r, "\pi"] \arrow[d, "f"] & X \\
a \arrow[r] & \hat{C} &
\end{tikzcd}