# FactoredFunctionUtilities R¶

mergeFactors(u, v) is used when the factorizations of spadvar{u} and spadvar{v} are known to be disjoint, e.g. resulting from a content/primitive part split. Essentially, it creates a new factored object by multiplying the units together and appending the lists of factors.
refine(u, fn) is used to apply the function userfun{fn} to each factor of spadvar{u} and then build a new factored object from the results. For example, if spadvar{u} were created by calling nilFactor(10, 2) then refine(u, factor) would create a factored object equal to that created by factor(100) or primeFactor(2, 2) * primeFactor(5, 2).