The frame problem is about what doesn't change when we describe annupdate to a state. For example, in a banking system, we mights say that after a transfer of fifty euros from customer A to customer B, the balance in A's account is fifty euros less and the amount in custome B's account is fifty euros more; but what about every other account? The frame problem is working ot the frame, the things outsoide of which are expected not to be affected. In the bank account example, the separation fo the accounts is pretty straightforwards, but the situation gers a lot more complicated if theer are constraints or rules that are triggered after updates, for example, if customer B's account has a rule that says money is transfered to savings once the balance goes over a particular value.
Defined on pages 29, 32
Used on Chap. 2: pages 29, 32, 33; Chap. 13: page 304
Also known as frame axiom