Acts A and B are exactly similar if they have all the same properties -- so that A has every property that B has, and vice versa.
Acts A and B are exactly similar if they have all the same properties -- so that A has every property that B has, and vice versa.
This is the correct definition.
While it may never happen in the real world that two actions have all the same properties in common, still we can apply the notion of "exact similarity" to hypothetical cases. To test our impartiality, we can imagine exactly similar actions in which the parties are in different places -- in which, for example, we are on the receiving end of the action.
Acts A and B are exactly similar if they have all the same properties -- so that A has every property that B has, and vice versa.
This is the correct definition.