Linear independence of intertwining operators

For an irreducible admissible representation of a connected reductive p-adic group, we consider standard intertwining operators holomorphic at zero. Using algebraic methods connected with the structure of linear algebraic groups, we control supports of particularly chosen functions from the induced space. We prove linear independence of standard intertwining operators. This is used to extend the definition of the R-group from a square integrable representation to its Aubert involution