The mathematical algorithm may be correct, but is the implementation of it correct and how do you verify it?

A computer program can not be proven to be correct in a number of relatively quick and easy ways.

Are you trying to say that paying more a the book guarantee that it has less environmental impact than if you'd paid less for it?

Or maybe what you're saying is that if the book was half the price you'd buy two, and that you're not disciplined enough to be environmentally conscious without being financially constrained.

My opinion is that the price of the book and its environmental impact are not directly connected. If you pay less for the book, you'll have money that will allow you to spend it on having less environmental impact elsewhere in your life.

Some forms of active suspension mean your car can have suspension matched to the weight of the car and its loads, you can have suspension matched to an empty car when its empty and matched to a fully laden car when its loaded up instead of having a compromise setup thats matched to neither laden or unladen. How many times have you seen a car where the rear is low because of the load of the passengers or the trailer its towing?

Other forms of active suspension means you can have soft suspension when you're driving in a straight line and only have stiffer suspension when you are cornering, the result is that you can make your "cornering" rates higher performance without sacrificing your "straight line" comfort.

Other forms again allow the car to stiffen is anti roll bars and to corner flat.

Citroen has produced suspension systems that do all of the above on production cars, their first systems (on the DS and later cars) only self levelled, later their Hydractive system on the XM had "hard" and "soft" settings too eventually the Activa system on the Xantia added active anti roll bars too.

Formula One cars used active suspension, it could vary suspension rates, ride heights and anti-roll stiffness, it gave the cars that had it a competitive advantage over those that didn't but was eventually banned.