Function ordered_pair_priority 

pub fn ordered_pair_priority(
    role: Role,
    local: Priority,
    remote: Priority,
) -> u64

§6.1.2.3’s pair priority with the operands put in the roles the formula names.

G is “the priority for the candidate provided by the controlling agent” — so which of the two candidate priorities is G is a fact about our role, not about the pair.