“…For this group, the Groebner basis with parameters (a,b,c,d) = (0,0,0,0) is quite simple: G mir−503−5p (0,0,0,0) = S (4A1) (x,y,z), which is the already mentioned Cayley cubic. For (a,b,c,d) = (1,1,0,0), G mir−503−5p (1,1,0,0) = −3xyzκ 3 (x,y,z), where κ 3 (x,y,z) is the Fricke surface described by Planat et al 38 For (a,b,c,d) = (1,1,1,1), there are several more polynomials. One of which defines the Fricke surface xyz + x 2 + y 2 +z 2 − 2x − y -2 = 0.…”