appendix A, typo in txid

appendix_bitcoin_fundamentals_review.asciidoc

@@ -318,7 +318,7 @@ image::images/mtln_aa09.png["A transaction chain showing the locking script (out
 To validate Bob's transaction, a Bitcoin node would do the following:
 
 . Extract the unlocking script from the input (+<Bob Signature>+).
-. Look up the outpoint it is attempting to spend (+a643e37...3213:0+). This is Alice's transaction and would be found on the blockchain.
+. Look up the outpoint it is attempting to spend (+a643e37...3212:0+). This is Alice's transaction and would be found on the blockchain.
 . Extract the locking script from that outpoint (+<Bob PubKey> CHECKSIG+).
 . Concatenate into one script, placing the unlocking script in front of the locking script (+<Bob Signature> <Bob PubKey> CHECKSIG+).
 . Execute this script on the Bitcoin Script execution engine to see what result is produced.