Routine call in UDF
 

In the UDF manual on page 4-85 there are an UDF example there they manipulate with the swelling index. In the routine they start off by calling the standard evaporation routine to calculate the mass and heat transfer [VaporazationLaw(p)].

My question: Why is this necessary. I thought that the definition of which laws to use was done elsewhere. Does this mean that when you use UDF's the other laws wont be used unless it is defined in the (first) UDF ? If not, can anyone see the reason why this call is necessary.

Cheers Christian