diff --git a/sose2021/algebra/alg2.pdf b/sose2021/algebra/alg2.pdf
new file mode 100644
index 0000000..202f6c1
Binary files /dev/null and b/sose2021/algebra/alg2.pdf differ
diff --git a/sose2021/algebra/alg2.xopp b/sose2021/algebra/alg2.xopp
new file mode 100644
index 0000000..09a470d
Binary files /dev/null and b/sose2021/algebra/alg2.xopp differ