 The opposite of unsuccessful formulas are the “successful” ones: these are the formulas that are true after they are announced. Here one should distinguish between “performative announcements” that bring about truth by their very occurrence (e.g., a judge says, “The objection is overruled”, which has the effect of making the objection overruled) and “informative announcements” that simply inform their listeners of truth (e.g., our mutual friend says, “I live on 207th Street”, which has the effect of informing us of something that is already true). Performative announcements are best addressed in a Dynamic Epistemic Logic setting using factual changes, a topic discussed in  Appendix G.  For now our concern will be with informative announcements. 