In the context of running a web service that accepts payments in Bitcoin, how can we use bitcoind to identify a transaction that has been replaced using BIP125 Replace-By-Fee?

When RBF is used, a new txid is created, resulting in two unique transactions. We show unconfirmed transactions to the sender, resulting in the tx that was originally replaced continuing to appear as 0-conf.

We have considered using the following logic but suspect there is a better way.

("confirmations" == 0) and ("bip125-replaceable" == "yes")

Looking up the original txid on blockchain.info results in "Transaction rejected by our node. Reason: Transaction was previously accepted but has been pruned from our database."