Very nice, semantics are clear and use cases are compelling.

Can we defer discussion of how to roll this out for a little bit, and see
if there is consensus that:

a) benefits of having this outweigh risks
b) we're all happy with exact semantics

Then we can have a knock-down drag-out argument about whether it should
roll out as a soft fork, wait for a hard fork, be combined with some other
things that it would be nice to add or change, etc.....

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Gavin Andresen