TY  - INPR
A1  - Egrot, ROB
A1  - Hirsch, ROBIN
JF  - Journal of Symbolic Logic
UR  - https://doi.org/10.1017/jsl.2021.88
SN  - 0022-4812
N2  - 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.
ID  - discovery10139073
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
Y1  - 2021///
AV  - public
TI  - FIRST-ORDER AXIOMATISATIONS of REPRESENTABLE RELATION ALGEBRAS NEED FORMULAS of UNBOUNDED QUANTIFIER DEPTH
ER  -