Peirce's theory of truth depends on two other, intimately related subject matters, his theory of "sign relations" and his theory of "inquiry". Inquiry is a special case of "semiosis", a process that transforms signs into signs while maintaining a specific relationship to an object, which object may be located outside the trajectory of signs or else be found at the end of it. Inquiry includes all forms of belief revision and logical inference, including "scientific method", what Peirce here means by "the right method of transforming signs". A sign-to-sign transaction relating to an object is a transaction that involves three parties, or a relation that involves three roles. This is called a "ternary or triadic relation" in logic. Consequently, pragmatic theories of truth are largely expressed in terms of triadic truth predicates.