added 7 ingredients for a payment channel protocol

topics.asciidoc

@@ -204,4 +204,15 @@ They have particular illustrative purpose and are therefore collected seperately
 * routing vs path finding
 
 ==== examples
-tba
+tba
+
+==== properties
+
+* the seven ingredients for a payment channel c.f: https://youtu.be/AcP3czefanM
+** 2-2 musig address
+** funding transaction to open the channel (without possibility to malleate the transaction)
+** commitment transaction to encode the balance of the channel
+** a time lock to remove trust
+** a communication protocol for partners exchange data outside of the bitcoin network
+** asymmetrical information (unless we switch to eltoo but even there not all keys are shared but channel state is symmetric)
+** game theoretic and economical incentives to follow the protocol