The Indep function is a placeholder for representing the independence-checking of a RootOf or of a set of RootOfs. It is used in conjunction with evala.

The call evala(Indep(S, 'r')) returns true if the RootOfs in S are independent, or false otherwise. In case relations are found, the name r is assigned the set of relations.

RootOfs representing algebraic numbers (or functions) are said to be independent if the polynomial defining a RootOf R is irreducible over the field generated by the RootOfs which do not contain R.