I assume you would consider “You will take this $10 if and only if Barack Obama is president of the United States.” true even if you were completely certain you would take the $10 if John McCain was President. If and only if this was the intended meaning I would agree with your conclusion.
I assume you would consider “You will take this $10 if and only if Barack Obama is president of the United States.” true even if you were completely certain you would take the $10 if John McCain was President. If and only if this was the intended meaning I would agree with your conclusion.