I think AKNSign can easily be replaced by Swift.FloatingPointSign (or even Bool). The only commonly used operation is xor which maps to !=. ANKSigned is neat, on the other hand, but I think it belongs in ANKSignedKit (unsurprisingly). What I still have to decide is whether ANKFixedWidthInteger needs init methods like exactly(sign:magnitude:) outside of ANKSignedKit.