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. 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 (-5[1])of a book that uses “H2O is water” (-5[1])as an example of an a (*) posteriori statement with this property, (-5[1])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” fixes a referent, thus creating rigid designators. Both this property and sufficiency hold for biconditional statements. (-5[1])For 10 points, a Saul Kripke (“KRIHP-kee”) book (10[1])is titled Naming and what word, which describes statements that must be true? (10[2])■END■