NoJoke..
I was merely pointing out that having an enquiring mind (without suitable guidance) can lead you into trouble...
Approximately on the thread...
A study of FCOM 3 Abnormals and QRH reveals that for CAT 3 DUAL you need 2 engines, 2 Engine GEN, and Electrical Split. If any one of those is INOP you lose CAT 3 DUAL capability. I don't teach the "why", just the "what to do next" bit, because life's too short...
Good luck with the search..
TP