An Ebb in practice.

Two windows, traced to the unit. The numbers are arithmetic, not promises: 2% of volume is the Draw, and outflow is what the Draw answers.

A window of heavy outflow

Say a window sees 40 ETH of buys and 55 ETH of sells — 95 ETH of volume in all.

• The Draw: 2% of 95 ETH, which is 1.9 ETH of value, gathering in the Shallows trade by trade.
• The reading: 40 minus 55 — net outflow of 15 ETH.
• The settlement: an Ebb. The gathered Draw buys EBBL from the market, and the bought units settle in the Silt. The supply falls by exactly what the Draw could buy.

The sellers paid for the answer to their own selling. That is the whole design in one sentence.

A quiet window on net inflow

Say a window sees 3 ETH of buys and 1 ETH of sells.

• The Draw: 2% of 4 ETH — 0.08 ETH of value — gathers in the Shallows.
• The reading: 3 minus 1 — net inflow of 2 ETH.
• The settlement: none. The Draw waits for the next window. Nothing is issued against the inflow; the supply is untouched.

Two rules to carry away: the Draw gathers in every window that has trades, and an Ebb settles only on outflow. Everything else is arithmetic.