Say the back price (odds) on a market is $2.5$.
Then the following time sequence happens:
Bettor $A$ places a back bet with price $2.6$, for $\$100$ (it will not match)
Then bettor $B$ places a back bet with price $2.6$ for $\$200$ (it will not match)
Then bettor $C$ places a lay with price $2.6$ for $\$100$.
What will be the matches? What is the match priority rule?
Bettor $A$ will have a full match for his $\$100$ back, because he was earlier?
Or will bettor $A$ have a $\$33.3$ and bettor $B$ will have a $\$66.7$ partial matches because the available offer will be divided proportionally on the current waiting non matched bets?
Neither of above, random, or this is not documented at all?
I've tried to find the answer, but did not even find similar questions on the web.