This is the second title concept of a 1947 book which describes a class of sentences called “state-descriptions” that contain either an atomic sentence or its negations. The letter K denotes a logical axiom that distributes this property. (-5[1])In the Barcan formula, this property is applied to statements containing the existential and universal quantifiers. This property is the last word in the title of a book that uses “H2O is water” as an example of an a (*) posteriori (-5[1])statement with this property, which is denoted with a box-shaped operator. This is the second concept in the title of a book that discusses how an “initial baptism” (10[1])fixes a referent, thus creating rigid designators. Both this property and sufficiency hold for biconditional statements. For 10 points, a Saul Kripke (“KRIHP-kee”) book is titled Naming and what word, (10[1])which describes statements that must be true? ■END■