Yes, clearly in some counterfactuals such knowledge works.
The reason we cannot use the knowledge from this particular counterfactual is that we have no knowledge about how the counterfactual was selected.
What do you additionally need to know about the counterfactuals? Where is the ambiguity (among what two examples of possible interpretations that change the analysis)? What do you mean by “selected”?
It may not be what wedrifid meant, but does Omega always appear after you see the result on the calculator? Does Omega always ask : ”Consider the counterfactual where the calculator displayed opposite_of_what_you_saw instead of what_you_saw” ?
If that is true, then I guess it means that what Omega replaces your answer with on the test sheet in the worlds where you see “even” is the answer you write on the counterfactual test sheet in the worlds where you see “odd”. And the same with “even” and “odd” exchanged.
Yes, clearly in some counterfactuals such knowledge works.
What do you additionally need to know about the counterfactuals? Where is the ambiguity (among what two examples of possible interpretations that change the analysis)? What do you mean by “selected”?
It may not be what wedrifid meant, but does Omega always appear after you see the result on the calculator?
Does Omega always ask :
”Consider the counterfactual where the calculator displayed opposite_of_what_you_saw instead of what_you_saw” ?
If that is true, then I guess it means that what Omega replaces your answer with on the test sheet in the worlds where you see “even” is the answer you write on the counterfactual test sheet in the worlds where you see “odd”. And the same with “even” and “odd” exchanged.