KRIPKE, Saul Aaron A Completeness Theorem in Modal Logic. (Thorild Dahlquist's copy )
Princeton: The Association for Symbolic Logic, 1959. First edition.

An absolutely mint copy of his first paper on modal logic which marks the beginning of Kripke Semantics. "Kripke made his early reputation as a logical prodigy, especially through work on the completeness of systems of modal logic. The three classic papers are 'Completeness Theorem in Modal Logic' (1959, Journal of Symbolic Logic), 'Semantical Analysis of Modal Logic' (1963, Zeitschrift für Mathematische Logik ...) and 'Sematical Considerations on Modal Logic' (1963, Acta Philosophica Fennica). ... Kripke sematics: The standard semantic treatment for modal languages with symbols for necessity and possibility, due to Saul Kripke. The model is a set of possible worlds and a relation on them, corresponding to the idea of one world being 'accessible' from another. A valuation function then evaluates sentences as true or false at worlds. Using these models, Kripke was able to bring new treatments to issues such as the decidability, independaance, and completeness of different systems of modal logic, where different conditions on the accessibility relation correspond to different strengths of system." (The Oxford Dictionary of Philosophy, pp.200-201). Provenance: With the signature of Swedish logician Thorild Dahlquist to the inside of the front wrapper.

In: The Journal of Symbolic Logic, Vol. 24, No. 1, March 1959, pp.1-14. The complete issue in original printed wrappers offered (mint condition).