Brogaard與Salerno認為，那些使用反例來證明各種反事實推理模式為無效的論證（簡稱「反例式論證」），犯了脈絡謬誤。這表示反例式論證在評價論證時，並沒有保持評價脈絡的不變，而這個脈絡上的改變可以追溯到評價論證時背景事實的改變。在這篇論文中，我們首先介紹Brogaard與Salerno如何以脈絡謬誤來挑戰反例式論證。其次，我們說明Cross如何基於反事實條件句的可能世界語意學來挑戰Brogaard與Salerno的論證，接著我們論證Cross的挑戰並不成立。最後，透過一個以知識論為基礎所建立的反例恰當性條件，我們企圖論證，任何以可能世界語意學為基礎的反例式論證，都無法恰當地顯示反事實推論模式的無效性。

Brogaard and Salerno argue that arguments which make key use of counter-examples to argue for the invalidity of various counterfactual inference patterns (henceforth, counter-example arguments) commit the contextual fallacy. This is because the contexts used in the evaluations of those examples do not remain fixed due to the variation in the background facts assumed in the evaluations. In this paper, we will first present their challenges, based on the contextual fallacy, to counter-example arguments. Second, we will argue against Cross’ objections to their challenges, which are based on Stalnaker-Lewis’ possible world semantics for counterfactuals. Finally, based on an epistemically-oriented adequacy condition for counter-example arguments, we will argue that no counter-example arguments based on possible world semantics can adequately be used to show the invalidity of various counterfactual inference patterns.