3 means that the growth of the money supply matches economic growth. so if there are more goods and services ("value") the money supply inflates to represent that, if there is less stuff, the money supply contracts. the result is the purchasing power of a monetary unit is constant year to year. not achievable but worth thinking about.

Figured I'd help articulate something, it is not achievable because it requires predicting what people will create using their imaginations and how the world will react to those creations, how they'll find utility and benefit from them in their lives. You can't adjust real time to economic growth because it is an organic, distributed process flowing from the creative mind.