Making a swap net.

We want both parties to agree on the swap protocol before hand.  

It is like a two sided symmetric payment screen. Each side confirming, then the message system executes.  The notary conditions for a recall posted. The message system cooperates with the chosen notaries.  But traders still carry credit ratings and notaries can read them, set reverse timeouts apriori, known to parties.  This works, spread sheet apps can be built against these rules.