A floor at zero

The last slide showed that the middle row folds away if every total passes onward unchanged. Our response rule needs to change at least some totals.

The weights on slide 16 were positive to make the first calculation easy. But a weight can also be negative. A positive weight adds. A negative weight subtracts.

For this demonstration, we chose:

cabernet +.20, viognier -.20, plummy +.20, apricotty -.20

Plummy cabernet produces:

+.20 + .20 = .40

Press apply the response rule. The positive .40 stays .40. It does not become 1.

For this bottle alone, we could still fold the calculation. The difference appears when the same unit sees another bottle.

Press try another bottle. Apricotty viognier produces:

-.20 - .20 = -.40

Apply the rule again. This time -.40 becomes 0.

Think of the rule as a floor at zero. Positive totals keep their value. Negative totals hit the floor and become 0.

Before the rule, this unit's totals across the four wines are .40, 0, 0, -.40. Those can be folded into direct weights. After the rule, it sends .40, 0, 0, 0.

That change from -.40 to 0 is the bend. Direct taste weights cannot reproduce it because each taste is shared by two bottles, the same problem we saw earlier.

A rule that turns a weighted total into an outgoing signal is an . This one is .