Here is my problem: I have several variables that I know are unknown and have arbitrary values. Let's call them C, C, and C. After doing some magic with Solve[ ... ] and Reduce[ ... ] and Simplify[ ... ], I get the expression:
Now, I know two things about these variables: they have arbitrary values, but each variable is an integer. So C spans Z, C spans Z, etc. Therefore, their sum spans Z. This is quite obvious. Mathematica gives me a conditional expression like
ConditionalExpression[C+C+C,C is in Integers && C is in Integers && C is in Integers]
Which is swell, but I know their sum is also an arbitrary integer. How would I tell Mathematica to replace C+C+C with C, C is in integers? Or to do this for arbitrary sums of unknowns, where the properties of the result are obvious but somewhat hard to read in their full form.