 $$\vcenter{\xymatrix@0@!0@R=0.0000em@C=0.0000em{& {\cdot} \ar[rd]^-{\sigma_{0}{\partial}_{0}\alpha}\\ {\cdot} \ar[ru]^-{\alpha} && {\cdot}}} \qquad\qquad \vcenter{\xymatrix@0@!0@R=0.0000em@C=0.0000em{& {\cdot} \ar