is it possible to invert a patch

[weepy]

I.e.

new_obj = apply(obj, patch)

remove(new_obj, path) // == obj

[Starcounter-Jack]

I understood your question as wether applied patches could be reverted.
I.e.

apply(obj,patch); // Make changes
revert(obj,patch); // Undo changes

Unfortunately the original values are lost when applying the patch and as the patch format itself is controlled by the RFC, I guess this would not be possible within the capabilities of the JSON Patch standard.

Let me know if I misunderstood the question and I'll reopen this issue.