When Does the AI Give Up???

[RERomine]

I'm fighting another campaign battle and the AI is pretty much toast. The battle is a delay and there are over 100 destroyed British tanks in my front and a like number of other vehicles. My casualties have been light and I'm trying to keep them that way so I'm holding my position. There are 29 turns remaining and aside from a few stray infantry units that pop up and get mauled every turn, the only action is inbound artillery. When does the AI decide enough is enough?