/*
 * NetBill Protocol
 */

constitutive:

sendRequest
	means 
		request,
		
		sendRequest
    if
        !quote & !goods &
        
        !sendRequest.


sendQuote
	means
	    quote,
		create(cc(mer, cus, cc(cus, mer, goods, pay), goods)),
        
        sendQuote
    if

        !sendQuote.

sendAccept
	means
		create(cc(cus, mer, goods, pay)),
		
		sendAccept
    if
        !pay &
        
        !sendAccept.

sendGoods
	means
		goods,
		create(cc(mer, cus, pay, receipt)),
		
		sendGoods
    if

        !sendGoods.

sendEPO
	means
		pay,
		
		sendEPO
    if
        
        !sendEPO.

sendReceipt
	means
		receipt,
		
		sendReceipt
    if
        pay &
        
        !sendReceipt.

regulative:
	quote ->. created(cc(cus, mer, goods, pay)) | created(c(cus, mer, pay)).
	created(cc(mer, cus, pay, receipt)) & goods ->. pay.
	pay .->. receipt.