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arXiv · 1305.6291

Semantics out of context: nominal absolute denotations for first-order logic and computation

Murdoch J. Gabbay
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Abstract

Call a semantics for a language with variables absolute when variables map to fixed entities in the denotation. That is, a semantics is absolute when the denotation of a variable a is a copy of itself in the denotation. We give a trio of lattice-based, sets-based, and algebraic absolute semantics to first-order logic. Possibly open predicates are directly interpreted as lattice elements / sets / algebra elements, subject to suitable interpretations of the connectives and quantifiers. In particular, universal quantification "forall a.phi" is interpreted using a new notion of "fresh-finite" limit and using a novel dual to substitution. The interest of this semantics is partly in the non-trivial and beautiful technical details, which also offer certain advantages over existing semantics---but also the fact that such semantics exist at all suggests a new way of looking at variables and the foundations of logic and computation, which may be well-suited to the demands of modern computer science.

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Murdoch J. Gabbay. 2013-05-27. Semantics out of context: nominal absolute denotations for first-order logic and computation. https://doi.org/10.1145/2700819

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