\begin{tikzcd}[column sep=small, row sep=small]
  & 1 & \\
  x \arrow[ur, no head] & & y \arrow[ul, no head] \\
  & 0 \arrow[ul, no head] \arrow[ur, no head] &
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small]
  & \vec{A} \arrow[dl] \arrow[dr] & & A^{\uparrow} \arrow[dl] \arrow[dr] & \\
  S = \mathfrak{X}_0 & & A = \mathfrak{X}_1 & & F = \mathfrak{X}_2
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small]
  & & A^{\llcorner\!\to} \arrow[dll, "\rho_S"'] \arrow[dl, "\uncertain{\sigma_2}"'] \arrow[d, "\sigma"] \arrow[dr, "\sigma_1"] \arrow[drr, "\rho_F"] & & \\
  \widetilde{S} \arrow[d, "\sigma_1"'] & \vec{A} \arrow[dl] \arrow[dr, "\sigma_1"] & \widetilde{A} & A^{\uparrow} \arrow[dl, "\sigma_2"'] \arrow[dr] & \widetilde{F} \arrow[d, "\sigma_2"] \\
  S & & A & & F
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small]
  & A^{\llcorner\!\to} \arrow[dl] \arrow[d] \arrow[dr] & \\
  \widetilde{S} \arrow[d] & A^{\wedge} \arrow[dl] \arrow[dr] & \widetilde{F} \arrow[d, no head] \\
  S & & F
\end{tikzcd}

\begin{tikzcd}[column sep=small, row sep=small]
  & y' \arrow[dr] & \\
  x \arrow[ur] \arrow[dr] & & z \\
  & y \arrow[ur] &
\end{tikzcd}