Clive D. W. Feather wrote:

Unless A860 is held to yellow if A864 is single yellow? Or have I
managed to misunderstand?

No, it sounds like you've got it exactly.

But, as I said, LU does it differently.


True. I'm just curious as to what the circuit that links the HR/HHR
relays at A864 with the GR relay at A860 looks like.