The program cvc.c is basically a copy of Marcus' program avc_exact2.c. This performs the contractions for the connected contributions to the vac. polarisation tensor from the conserved vector current with point sources. The result is Pi_mu_nu(q^2). This can be analysed with analyse_piq.c which is also copied form Marcus. Additionally to the moduls needed for cvc analyse_pi_q.c needs make_q2orbits.c (&.h) which mainly computes the lattice momenta qhat^2.