realpart(f(x))



Dear all,

Sorry to ask a lot of question that are maybe obvious if you have worked with 
maxima for a longer time than I have...

Anyway, I am running a database to test my implementation of Kovacic' 
algorithm and for one of the cases (kamke 2.78) I get as a result something 
including the integral of realpart(f(x)) and something with the integral of 
imagpart(f(x)). I want to get rid of the imagpart by imposing that f(x) is a 
real function

I think declare only accepts atoms, so I cannot do declare(f(x),real).
I can also not do depends(f,x) and then declare(f,real) because unfortunately 
integration doesn't know about dependencies. 
Another possibility is to simply use substitution, but I would prefer 
something more elegant if it exists.
Any suggestions?

Best,
Nijso