Deflation, however, will result when productivity increases as a consequence of automation, computerization, mechanization and/or roboticization!
Production may well decline as new products made in a more precise fashion by machines last longer.
Case in point ~ automotive engines (gasoline and diesel) are not only less costly (discounting for inflation) but they last longer. They are also vastly more productive than they were 50 years ago (in terms of MPG).
Employment in the truck engine industry has declined precipitously.
One interesting tidbit I hadn't expected in the automation of the factory I used to work at is that you can shut it down, leave it there for a couple of years DOING NOTHING, and walk in some morning and start it up without any disastrous consequences.
Even the machines that make the machines are far better, safer to use, and last longer. Retooling just isn't the problem it had been for such a long time.
Neither deflation nor inflation, the same crittur, just different levels-positive and negative- has anything at all to do with those processes or with any sort of productivity or production. None. Not. Inflation is entirely and only an increase in the money supply. That is the definition of the term. If you wish to use it for whatever else comes to mind you are effectively trying to construct analogies that don't work. Increased productivity when the economy is expanding makes for more total production. If the money supply does not increase then prices fall. That is not deflation. It is a reduction in the price level because the same money is chasing more goods. If the money supply is increased at the same rate that production increases then you have absolute inflation but no relative inflation. You have a stable average price level. When (not if) the government increases the money supply at a higher rate than the increase in production then you have
Iinflation, relative and absolute. When production is decreasing and the money supply is increasing you have Keynesian prosperity i.e. the numbers all show "expansion" but prices are rising generally and people in the real world are tightening their belts and losing their jobs i.e. becoming poorer.
The definition of Inflation/Deflation is a textbook thing. In the basic economics textbooks it is purely the increase/decrease in the money supply. In MBA-Finance textbooks it is confused with any sort of increase or decrease in prices, and value. Keynesians, who write most of the finance books do not and really cannot distinguish between a rise in a particular price and a general price rise and changing quantities of money in circulation.