Computing most general unifiers in Euclidean modal logics

Quentin Gougeon (1, 2)

1 UT3 - Université Toulouse III - Paul Sabatier
2 IRIT-LILaC - Logique, Interaction, Langue et Calcul

We prove that all extensions of K5 have unary unification. Our result applies to the parametric and relative variants of unification. In addition, our proof is constructive in the sense that we can effectively compute, in 4-exponential space, a most general unifier for any unifiable formula. We also investigate special unification types: we show that K5 and KD5 are transparent, and characterize the projective extensions of K5.

Keywords: Modal logic; Unification; Duality theory; Euclidean relations

Domains: Computer Science [cs]

Quentin Gougeon. Computing most general unifiers in Euclidean modal logics. 2023. ⟨hal-04244893⟩