prefixes - Proper usage of Prefix "UN" is there a word as "UNSWAPPING"

The interesting thing about "unswapping" (putting exactly two things, which have been swapped, back into their original positions) is that it is semantically equivalent to "re-swapping" and logically equivalent to "swapping". It's just another swap.

And after you do this, the two things might SEEM "unswapped", but they will have been swapped twice!

So, yes, you could use unswap, but there are better alternatives. In my opinion, you would be more easily understood (as restoring a prior state) if you said "swap(ped/ping) back".

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