6 papers
Dialectica Categories over Heyting Algebras
Colin Bloomfield, Peter Jipsen, Valeria de Paiva
Categorification---the process of constructing a categorical model of a piece of mathematics---often identifies a common abstraction that connects formerly unrelated but known stru…
Balanced residuated partially ordered semigroups
Stefano Bonzio, José Gil-Férez, Peter Jipsen +2
A residuated semigroup is a structure where is a poset and is a semigroup such that the…
Residuated lattices do not have the amalgamation property
Peter Jipsen, Simon Santschi
We show that the variety of residuated lattices does not have the amalgamation property, thereby settling a long-standing open problem. In addition, we show that the amalgamation p…
The logic of bunched implications is undecidable
Nick Galatos, Peter Jipsen, Søren Brinck Knudstorp +1
The logic of bunched implications (BI), introduced by O'Hearn and Pym (1999), has attracted significant attention due to its elegant proof calculus, varied semantics, and close con…
Duality theory and representations for distributive quasi relation algebras and DInFL-algebras
Andrew Craig, Peter Jipsen, Claudette Robinson
We develop dualities for complete perfect distributive quasi relation algebras and complete perfect distributive involutive FL-algebras. The duals are partially ordered frames with…
Locally Integral Involutive PO-Semigroups
José Gil-Férez, Peter Jipsen, Melissa Sugimoto
We show that every locally integral involutive partially ordered semigroup (ipo-semigroup) , and in particular every locally integral involutive…