witnessed

Witnessed holds the number of unsettled fast blocks the record can prove. Every block counted in it lies between two observations that the record made itself, and each of those observations found the slow clock standing where it had stood before.

The unit is fast blocks.¹ No part of the total is expressed in seconds, because seconds would be an interpretation of block cadence and cadence is a property of the sequencer rather than of the record.

The total is the sum of closed intervals and nothing else. An interval that is still open contributes nothing until a mark closes it, and an interval whose opening was never seen contributes nothing at all.

Because it accumulates only closed spans, witnessed moves in steps rather than continuously. Between steps it stands still even while unsettled time continues to pass.

One instruction writes witnessed. A mark reads the fast clock and the slow clock in the same transaction, compares the slow clock against the value stored at the previous mark, and where the slow clock has not moved it closes the interval between the two marks.

The span added is the difference between the two fast block numbers. Nothing is scaled, weighted or adjusted. The number that enters the total is the number the chain produced between the two reads.

Where the previous mark is missing, the interval has no observed start and the span cannot be added.¹ The mark still lands, still stores its own reading, and still opens an interval for the next caller.

No other instruction touches the field. Advance, lapse and sweep read it and none of them write it.

Witnessed cannot be reduced. There is no instruction that lowers it, no path through the contract that clears it, and no caller with the standing to try.

It cannot be corrected. A span written under a mistaken reading remains written, because correction would require an authority to decide which of two readings was true and no such authority exists here.

It cannot be transferred. The total belongs to the record rather than to any address, and the addresses that produced it appear in the register beside their marks and nowhere else.

It has no cap. The ladder of bands ends, but the field does not, and after the last band is crossed witnessed continues to accumulate with nothing further to reach.

The number is a floor on how much unsettled time actually passed. It is never an estimate of that quantity, and the true figure is always at least as large as the one printed.

Read alone, witnessed says nothing. Set it against elapsed.¹ A small witnessed on a young record and a small witnessed on an old record describe opposite situations, and the field cannot distinguish them by itself.

Set against dark, the same total says how much of the passing time had someone present for it. Set against marks, it says how much each act of attention was worth.

The register below lists the contributions in order, so the total can be recomputed without trusting the stored value.