eprintid: 10139073 rev_number: 12 eprint_status: archive userid: 608 dir: disk0/10/13/90/73 datestamp: 2021-11-25 08:10:58 lastmod: 2021-11-25 08:10:58 status_changed: 2021-11-25 08:10:58 type: article metadata_visibility: show creators_name: Egrot, ROB creators_name: Hirsch, ROBIN title: FIRST-ORDER AXIOMATISATIONS of REPRESENTABLE RELATION ALGEBRAS NEED FORMULAS of UNBOUNDED QUANTIFIER DEPTH ispublished: inpress divisions: UCL divisions: B04 divisions: C05 divisions: F48 note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: Using a variation of the rainbow construction and various pebble and colouring games, we prove that RRA, the class of all representable relation algebras, cannot be axiomatised by any first-order relation algebra theory of bounded quantifier depth. We also prove that the class At(RRA) of atom structures of representable, atomic relation algebras cannot be defined by any set of sentences in the language of RA atom structures that uses only a finite number of variables. date: 2021 date_type: published official_url: https://doi.org/10.1017/jsl.2021.88 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1902818 doi: 10.1017/jsl.2021.88 lyricists_name: Hirsch, Robin lyricists_id: RHIRS08 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: Journal of Symbolic Logic issn: 0022-4812 citation: Egrot, ROB; Hirsch, ROBIN; (2021) FIRST-ORDER AXIOMATISATIONS of REPRESENTABLE RELATION ALGEBRAS NEED FORMULAS of UNBOUNDED QUANTIFIER DEPTH. Journal of Symbolic Logic 10.1017/jsl.2021.88 <https://doi.org/10.1017/jsl.2021.88>. (In press). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10139073/1/first-order-axiomatisations-of-representable-relation-algebras-need-formulas-of-unbounded-quantifier-depth.pdf