RFC 0454: How to handle Ack messages that have a non OK state?

[karimStekelenburg]

Looking at the diagram of 0454 (present-proof-v2) I noticed that whenever an ack message is received, it assumes this message indicates a 'positive acknowledgement'. However 0015 (ack) contains a status field that can be either OK, FAIL or PENDING.

Looking at the diagram of 0454 (present-proof-v2) I get the idea that the verifier only is supposed to send an ack message with an OK status, and otherwise is expected to send a problem-report.

So my question here is, what to do if the verifier sends an ack message with the status set to FAIL?

[TelegramSam]

DIscussed WG 20220316. Should be an ACK-ok, or a Problem Report, not an ACK-fail. Needs explaining text added to relevant RFCs. Also update please-ack decorator. Stephen Curran volunteered.