### Abstract

It is well known that the modal logic S5 can be embedded in the classical predicate logic by interpreting the modal operator in terms of a quantifier. Wajsberg [10] proved this fact in a syntactic way. Mints [7] extended this result to the quantified version of S5; using a purely proof-theoretic method he showed that the quantified S5 corresponds to the classical predicate logic with one-sorted variable. In this paper we extend Mints� result to the basic modal logic S4; we investigate the correspondence between the quantified versions of S4 (with and without the Barcan formula) and the classical predicate logic (with one-sorted variable). We present a purely proof-theoretic proof-transformation method, reducing an LK-proof of an interpreted formula to a modal proof.

Original language | English |
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Pages (from-to) | 1403-1414 |

Number of pages | 12 |

Journal | Journal of Symbolic Logic |

Volume | 68 |

Issue number | 4 |

DOIs | |

Publication status | Published - 2003 Dec |

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### ASJC Scopus subject areas

- Philosophy
- Logic

### Cite this

*Journal of Symbolic Logic*,

*68*(4), 1403-1414. https://doi.org/10.2178/jsl/1067620195