72 Minutes and Bentching

I was at a wedding and I washed for bread it's now been more than 72 minutes since I last ate bread do I still bench what if I'm still in the same room what if I already left the hall do I have to go back to bench how does it work with weddings and bread so there really two Halas when it comes to benching on bread one ala is 72 minutes a person just ate one kazas of bread the the minimum amount of bread how long does he have in order to be able to bench he has 72 minutes if a person eats more bread or other Foods together with the meal the amount of time he has is till he is hungry again so long as he is still satiated from what he ate then it could be much much longer than 72 minutes 72 minutes is actually the minimum amount of time that you have to bench it could be hours person goes to a wedding and he had a roll of bread he had chicken he could go 2 three hours and he's still not hungry he could still bench he does not lose the benching if he left the hall he forgot to bench really is that he's supposed to go back if that would be too difficult then he benches wherever he is