Revert "Add shortcut for big frak M"

This reverts commit 7e0e9e827a4f4113f2fd12fe11084c47f2dc62f9.
Revert "Revert "Add shortcut for big frak M""

This reverts commit ba867eb4e1b974184ea2dcc264eecda2151f4fb2.
lect4 part 4