The symmetries of the 2phi1
  We show that the only symmetries of the 2phi1 within a large class of possible transformations are Heine's transformations. The class of transformations considered consists of equation of the form 2phi1(a,b;c;q,z)= f(a,b,c,z) 2phi1(L(a,b,c,q,z)), where f is a q-hypergeometric term and L a linear operator on the logarithms of the parameters. We moreover prove some results on q-difference equations satisfied by 2phi1, which are used to prove the main result. 
F.J. van de Bult