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Unification in intuitionistic logic

Published online by Cambridge University Press:  12 March 2014

Silvio Ghilardi
Silvio Ghilardi*
Affiliation:
Dipartimento di Scienze Dell' Informazione, Universita ‘Degli’ Studi di Milano, Via Comelico 39/41, 20135 Milano, Italy E-mail: ghilardi@dsi.unimi.it
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Abstract

We show that the variety of Heyting algebras has finitary unification type. We also show that the subvariety obtained by adding it De Morgan law is the biggest variety of Heyting algebras having unitary unification type. Proofs make essential use of suitable characterizations (both from the semantic and the syntactic side) of finitely presented projective algebras.

Keywords

E-unificationprojective Heyting algebrasexact formulasadmisssible inference rules
Type
Research Article
Information
The Journal of Symbolic Logic , Volume 64 , Issue 2 , June 1999 , pp. 859 - 880
Copyright
Copyright © Association for Symbolic Logic 1999

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References

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