Thanks I think I got it .

I will always compare the carrying amount of the debt with the FV of the asset, equity or wahever is used to pay to determine debt gain (extraordinary if apply). 

Gains are splitted in ordinary gain (NBV of asset-FV asset) and debt rest. gain (FV-Carrying amount of debt).

And based on the example CPATx gave if paying back with equity I take  FV of stocks.  In conclusion FV of anything used to pay.

I can handle the clasification of Extraordinary. The confusion was in the comparison of so many gains.  I get loss sometimes with so many "fancy words" in English.

Thank you guys. I appreciate your explanations.