PP-2020-22: Adam-Day, Sam and Bezhanishvili, Nick and Gabelaia, David and Marra, Vincenzo (2020) The nerve criterion and polyhedral completeness of intermediate logics. [Pre-print]
| Preview | Text nerves.pdf Download (378kB) | Preview | 
Abstract
We investigate a recently-devised polyhedral semantics for intermediate logics, in which formulas are interpreted in n-dimensional polyhedra. An intermediate logic is polyhedrally complete if it is complete with respect to some class of polyhedra. We provide a necessary and sufficient condition for the polyhedral-completeness of a logic. This condition, which we call the Nerve Criterion, is expressed in terms of the so-called ‘nerve’ of a poset, a construction which we employ from polyhedral geometry.
The criterion allows for the investigation of the polyhedral completeness phe- nomenon using purely combinatorial methods. Utilising it, we show that there are continuum many intermediate logics that are not polyhedrally-complete. We also provide a countably infinite class of logics axiomatised by the Jankov-Fine formulas of ‘starlike trees’, which includes Scott’s Logic, all of which are polyhedrally-complete.
| Item Type: | Pre-print | 
|---|---|
| Report Nr: | PP-2020-22 | 
| Series Name: | Prepublication (PP) Series | 
| Year: | 2020 | 
| Subjects: | Logic Mathematics | 
| Depositing User: | Nick Bezhanishvili | 
| Date Deposited: | 17 Sep 2020 11:10 | 
| Last Modified: | 17 Sep 2020 11:10 | 
| URI: | https://eprints.illc.uva.nl/id/eprint/1759 | 
Actions (login required)
|  | View Item | 
 
        