It sucks that activitypub is so under specified.

[thenexusofprivacy@hachyderm.io]

Does that mean Undo(Block(Undo)) is also valid? And (Block(Undo(Block(Undo)))?

@hrefna @jenniferplusplus @ivy

[jenniferplusplus@hachyderm.io]

@thenexusofprivacy @hrefna @ivy it's very difficult to produce an invalid AP document. It's a little more interesting to discuss whether it's meaningful or legible, but that's a matter of convention, not specification.