If transaction has impossible locking script, are coins lost? If a bitcoin transaction's outputs have a locking script that is basically unsolvable, are the bitcoins lost, or can the transaction be invalidated?  (Or something else?)
If it made it into the blockchain, meaning 1 confirmation or more, it practically can't be invalidated. The same feature prevents people from reversing payments.

If it's provably unsolvable, then there's no way to spend the coins, and they're practically destroyed.