Standard generators of the Rudvalis group Ru are a and b where a is in class 2B, b is in class 4A and ab has order 13. (Source: ATLAS)
Standard generators of the double cover 2.Ru are preimages A and B where B is in class +4A and AB has order 13. An equivalent condition to B being in class +4A is that ABABB has order 29. (Source: ATLAS)
