Bacon's cipher: An Intro to Steganography

If I've understood well your construction, the complex $\hom_k(A,k)$ is the Hochschild complex of the cochain $k$-algebra $C^\star(X,k)$ of the (discrete) space $X$ with coefficients in the $C^\star(X,k)$-module $k$. The $C^\star(X,k)$-module structure on $k$ is given via the augmentation $C^\star(X,k)\rightarrow k$ induced by the inclusion of the base point in $X$. Therefore

$$H_\star\hom_k(A,k)\cong HH_\star(C^\star(X,k),k).$$

Since $X$ is discrete then $C^\star(X,k)=k\times\stackrel{n}\cdots\times k=k^n$ concentrated in degree $0$, where $n=|X|$ is the number of points. Now the Künneth formula shows that

$$H_0\hom_k(A,k)\cong HH_0(C^\star(X,k),k)\cong k,$$

$$H_d\hom_k(A,k)\cong HH_d(C^\star(X,k),k)=0,\quad d\neq 0,$$

Therefore

$$H^0A\cong k,$$

$$H^dA=0,\quad d\neq 0.$$


On standard melee maps, this option applies to:

  • destructible rocks
  • Xel'Naga Towers. Tooltip: "Provides vision to nearby units".
  • neutral bunkers
  • Unbuildable Plates. Tooltip: "Unbuildable Plates".
  • Debris. Tooltip: "Attack this to destroy it".

But not to things like

  • critters
  • minerals or gas geysers

I'm concluding that the option only applies to map elements which are interactive in some form.


You may also want to take a look at the "Global Publisher Layout" and check what Quick Actions you have in the Publisher Layout.

For example, if the "Post" action is included there and is the first one in the list, you should see the "Post" publisher in your Chatter page. You use that publisher to create a text feed item.