diff --git a/09_channel_operation.asciidoc b/09_channel_operation.asciidoc
index f87d704..3b10214 100644
--- a/09_channel_operation.asciidoc
+++ b/09_channel_operation.asciidoc
@@ -76,7 +76,7 @@ Alice sends the `update_add_HTLC` Lightning message to Bob. This message is defi
 
 +amount_msat+:: This is the amount (value) of the HTLC in millisatoshis. In our example this is 50,200,000 millisatoshis (i.e., 50,200 satoshis).
 
-+payment_hash+:: This is the payment hash calculated from Dina's invoice. It is +H = RIPEMD160(SHA-256(R))+, where `R` is Dina's secret that is known only by Dina and will be revealed if Dina is paid.
++payment_hash+:: This is the payment hash calculated from Dina's invoice. It is _H_ = RIPEMD160(SHA-256(_R_)), where _R_ is Dina's secret that is known only by Dina and will be revealed if Dina is paid.
 
 +cltv_expiry+:: This is the expiry time for this HTLC, which will be encoded as a timelocked refund in case the HTLC fails to reach Dina in this time.