The Geometry of Relevant Implication II

This note extends earlier results on geometrical interpretations of the logic KR to prove some additional results, including a simple undecidability proof for the four-variable fragment of KR

Relevant Implication and Ordered Geometry

This paper shows that model structures for R+, the system of positive relevant implication, can be constructed from ordered geometries. This extends earlier results building such model structures from projective spaces. A final section shows how such models can be extended to models for the full system R

Relevant Implication and Ordered Geometry

This paper shows that model structures for R+, the system of positive relevant implication, can be constructed from ordered geometries. This extends earlier results building such model structures from projective spaces. A final section shows how such models can be extended to models for the full system R