former

I don’t get this part:
:: Since you gave $ PV to charity, Government forgoes tax (T oi) on equal amount of your income. For example, if you donate 100,000 to a charity, you don’t need to worry about paying taxes on the 100,000 which you are donating, and IN ADDITION TO THAT you get a tax exemption on 100,000 of your, OTHER, income . So, in your case you saved ( PV * Toi ) on taxes, because of your donation.
The 100K should be coming from after-tax funds. You already paid taxes on it. Your post gives the impression that you get a tax deduction on part of PRE-TAX income which is impossible