Inquire on combustion module

[fracenvi]

Hello,

I got a question regarding the combustion module and how the components ym_fuel, ym_oxyd and ym_prod are obtained and transported in the case where i adopt diffusion flames. From what i understood, their evaluation relies solely on the use of the mixture fraction, by itself evaluated by extracting some sort of values from a rectangle-Dirac PDF. Now, from the moment i'm running a case where i manually deactivate the gas mass fractions integration (in the src/cogz/d3pint.f90 file), why do they keep appearing in post processing? Where else does their computation happen?

Thanks to anyone who can help,
Francesco