Update bitcoin-fundamentals-review.asciidoc

Co-authored-by: Mark Erhardt <murch@murch.one>

bitcoin-fundamentals-review.asciidoc

@@ -136,7 +136,7 @@ The fundamental building block of a bitcoin transaction is a transaction output.
 .A transaction transfers value from inputs to outputs
 image::images/tx1.png["transaction inputs and outputs"]
 
-Bitcoin full nodes track all available and spendable outputs, known as _unspent transaction outputs_, or UTXO. The collection of all UTXO is known as the UTXO set and currently numbers in the millions of UTXO. The UTXO set grows as new UTXO is created and shrinks when UTXO is consumed. Every transaction represents a change (state transition) in the UTXO set, by consuming one or more UTXO as _transaction inputs_ and creating one or more UTXO as its _transaction outputs_.
+Bitcoin full nodes track all available and spendable outputs, known as _unspent transaction outputs_, or UTXO. The collection of all UTXO is known as the UTXO set and currently numbers in the millions of UTXO. The UTXO set grows as new UTXO are created and shrinks when UTXO are consumed. Every transaction represents a change (state transition) in the UTXO set, by consuming one or more UTXO as _transaction inputs_ and creating one or more UTXO as its _transaction outputs_.
 
 For example, let's assume that a user Alice has a 100,000 satoshi UTXO that she can spend. Alice can pay Bob 100,000 satoshi, by constructing a transaction with one input (consuming her existing 100,000 satoshi input) and one output that "pays" Bob 100,000 satoshi. Now Bob has a 100,000 satoshi UTXO that he can spend, creating a new transaction that consumes this new UTXO and spends it to another UTXO as a payment to another user, and so on.