 Nonetheless, what a speaker conventionally implicates is not a part of what the speaker says.U's doing "x" might be his uttering the sentence "She was poor but she was honest".What "U" meant, and what the sentence means, will both contain something contributed by the word "but", and I do not want this contribution to appear in an account of what (in my favored sense) "U" said (but rather as a conventional implicature).