Let's say we have a zero real interest rate to simplify matters, since it is the same for both inflation and deflation. Also, we started with a condition that we are profitable at 0% inflation. What will your example be in these conditions, for inflation and deflation, please.
Of course, the real interest has to be larger than the deflation rate (which it normally is). Otherwise, you will never get a loan !
We are not talking about loans! We are talking about producers who don't necessarily take loans but work on their own capital.