 act of verbal behavior. Another thing to think of is formal similarity. Formal similarity. I hope we don't get charged for that jingle. Anyway, so formal similarity is when the sense mode matches the antecedent stimulus and the response. So for instance, if I go, hi Ryan. And I write down, Brad said hi. Or I say, hi Brad, on paper. On paper. Keyword on paper, that is not formal similarity. And if I go, formal similarity. And I say, formal similarity. There you go. Formal similarity.