 (3a)  is used with its conventional meaning in (4a) as the consequent of a conditional. But because  (3c)  is a conjunct of the antecedent of that conditional, (4a) itself does not imply in any way that being brave follows from being English. A speaker asserting [4a] does not say [3a] and does not mean [3c]. So the speaker does not implicate that being brave follows from being English. The antecedent of [4a] prevents the conversational implicature of its consequent from “projecting”. The implicature triggered by the appositive is not implicated for a completely different reason in (4b). When this sentence is used ironically, the speaker uses it with its conventional meaning and says that Trump, the stable genius, started a trade war. But because it is used to mock Trump’s claim that he is a stable genius, the speaker does not implicate that Trump is a stable genius. Indeed, he implicates the very opposite. The meaning of a sentence determines its conventional implicatures, but whether a speaker implicates them depends on how the sentence is used. The speaker does implicate them when the sentence is used to assert what the sentence means. The same is not always true for conversational implicatures.