I always thought the cost of capital (borrowing money) in real terms already included inflation. And then the nominal interest rate is equal to inflation plus profit margin for lenders.
The cost of borrowing money in NOMINAL terms you mean (the actual rate you have to pay) includes, as you say, inflation and indeed, the expected profit margin for the lenders, which is exactly the real interest rate.
Then the real interest would be equal to nominal one in case there is no inflation?
So, as I understood your reasoning, you still consider as losses anything which the producer gets above the inflation rate but below inflation plus lenders interest, i.e. nominal interest? Even if he is not borrowing, right?