Topic: Is it possible to have a combination of tags give a post another tag?

Essentially many posts have both 3d and animation, but they don't have the 3d_animation tag. Could we make it so that if a post has both 3d and animation as tags the post would automatically get the 3d_animation tag?

The CG part of post #1696123 isn't animated, and so this post, as well as any others which would end up using mixed media in the same fashion, would completely invalidate the tag combo.