  We compute the Green functions and correlator functions for N twist fields
for branes at angles on T^2 and we show that there are N-2 different
configurations labeled by an integer M which is roughly associated with the
number of obtuse angles of the configuration. In order to perform this
computation we use a SL(2,R) invariant formulation and geometric constraints
instead of Pochammer contours. In particular the M=1 or M=N-1 amplitude can be
expressed without using transcendental functions. We determine the amplitudes
normalization from N -> N-1 reduction without using the factorization into the
untwisted sector. Both the amplitudes normalization and the OPE of two twist
fields are unique (up to one constant) when the \epsilon <-> 1-\epsilon
symmetry is imposed. For consistency we find also an infinite number of
relations among Lauricella hypergeometric functions.
