I'm looking at 3 forms of capital maintenance. How do these get applied in practice? I can't figure it out:

1. Nominal dollar. Seems simple, "ending capital - beginning capital" = profit
2. Purchasing power. Same as nominal except takes into account inflation. How does this affect journal entries, accounts, and financial statements? I have no idea how this works.
3. Physical (productive capacity) capital maintenance. Book says "profit = cost of assets used - cost to replace assets used". I have no idea how this applies in practice, journal entries, accounts, financial statements. What the hell is this?

As far as I know, there's just nominal, and some values are adjusted for conservatism purposes, or future portions are discounted to present value.

I don't really get where purchasing power & physical capital maintenance come into play???