In detail, the set of discrete symmetries we are going to consider are the ones that respect the OPEs of the fields and fix the N=4 superconformal algebra. Peculiarity of K3 surfaces is that, when a d=10 IIA or IIB superstring theory with 32 supercharges is compactified on them, only 16 supercharges are preserved and this gives birth to 6 dimensional low energy theories of supergravity. If we compactify on (K3 x T^2) surfaces, what we obtain are low energy…