13   Mat          A, A11, A12, A21, A22;  in main()  local
85   PetscCall(MatCreate(PETSC_COMM_SELF, &A22));  in main()
86   PetscCall(MatSetSizes(A22, size2, size2, size2, size2));  in main()
87   PetscCall(MatSetType(A22, MATSEQDENSE));  in main()
88   PetscCall(MatSeqDenseSetPreallocation(A22, b + size1 * size + size1));  in main()
89   PetscCall(MatDenseSetLDA(A22, size));  in main()
90   PetscCall(MatAssemblyBegin(A22, MAT_FINAL_ASSEMBLY));  in main()
91   PetscCall(MatAssemblyEnd(A22, MAT_FINAL_ASSEMBLY));  in main()
105   PetscCall(MatMult(A22, X2, Z2));  in main()
124   PetscCall(MatSetValues(A22, 1, &i, 1, &j, &v, INSERT_VALUES));  in main()
129   PetscCall(MatAssemblyBegin(A22, MAT_FINAL_ASSEMBLY));  in main()
130   PetscCall(MatAssemblyEnd(A22, MAT_FINAL_ASSEMBLY));  in main()
135   PetscCall(MatMult(A22, X2, Z2));  in main()
147   PetscCall(MatMultTranspose(A22, X2, Z2));  in main()
161   PetscCall(MatDestroy(&A22));  in main()