11 citations · 43 across the 14 of their papers we have counts for
8 papers · 1 filter
EXPTIME-hardness of higher-dimensional Minkowski spacetime
Robin Hirsch, Brett McLean
We prove the EXPTIME-hardness of the validity problem for the basic temporal logic on Minkowski spacetime with more than one space dimension. We prove this result for both the ligh…
A corrected strategy for proving no finite variable axiomatisation exists for RRA
Rob Egrot, Robin Hirsch
We show that if for all finite there is a pair of non-isomorphic finite digraphs satisfying some additional conditions, one of which is that they cannot be distinguished in a c…
Temporal Logic of Minkowski Spacetime
Robin Hirsch, Brett McLean
We present the proof that the temporal logic of two-dimensional Minkowski spacetime is decidable, PSPACE-complete. The proof is based on a type of two-dimensional mosaic. Then we p…
First-order axiomatisations of representable relation algebras need formulas of unbounded quantifier depth
Rob Egrot, Robin Hirsch
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…
The temporal logic of two-dimensional Minkowski spacetime with slower-than-light accessibility is decidable
Robin Hirsch, Brett McLean
We work primarily with the Kripke frame consisting of two-dimensional Minkowski spacetime with the irreflexive accessibility relation 'can reach with a slower-than-light signal'. W…
The Temporal Logic of two dimensional Minkowski spacetime is decidable
Robin Hirsch, Mark Reynolds
We consider Minkowski spacetime, the set of all point-events of spacetime under the relation of causal accessibility. That is, can access if an electromagnetic…
The algebra of functions with antidomain and range
Robin Hirsch, Marcel Jackson, Szabolcs Mikulás
We give complete, finite quasiequational axiomatisations for algebras of unary partial functions under the operations of composition, domain, antidomain, range and intersection. Th…
There is no finite-variable equational axiomatization of representable relation algebras over weakly representable relation algebras
Jeremy F. Alm, Robin Hirsch, Roger D. Maddux
We prove that any equational basis that defines RRA over wRRA must contain infinitely many variables. The proof uses a construction of arbitrarily large finite weakly representable…