receiver, such that the payment sender is fully committed, and cancelled or executed conditionally at a later time.sender other than it will have a longer-than-normal expiry parameter.receiver exposes a preimage that hashes to a payment_hash of an Invoice and withdrawing the locked funds. When a sender's funds are committed there is no option but to wait until hashlock resolution (completing the payment) or timelock tl expiration (canceling the payment). By setting a long enough tl, a payment receiver has the option to withhold (or cancel) resolution after funds have been committed until a time t such that t < tl, otherwise tl expires (t >= tl) and funds are returned back to the sender. The conditions by which the receiver settles or cancels the invoice can be arbitrary or cryptographically conditional (ie. the receiver does not know the preimage and must obtain it to settle the payment).item delivery Shop, a Customer could generate a hash of a preimage and send it to the Shop. The Shop generates an invoice with payment_hash equal to hash and Customer pays it, however the Shop cannot settle it without preimage. Upon item delivery the Customer reveals the preimage to the Shop Courier who then settles the invoice.item Shop, an independent Courier, and a shop Customer:preimage and sends hash of preimage to the Shopinvoice0 and Customer pays ithash to the Courier who creates another hodl invoice invoice1 (for delivery costs) with the same payment_hash and Shop pays itpreimage to the Courier who settles invoice1 revealing the preimage to Shop who then settles invoice0.preimage and sends hash to Bobpayment_hash equal to hashpreimage to settle the hodl invoicepayment_hash across multiple invoices to create conditional payment chains incurs risk for all parties receiving the preimage after it has been revealed once as intermediate nodes on mutual payment paths will access the preimage that can be used to claim funds before the respective HTLC resolution is complete, thereby potentially blocking settlement by the hodl invoice holder.