Temporal Primitives, an Alternative to Allen Operators

Allen Interval Algebra introduces a set of operators, which describe any possible temporal association between two valid time intervals. The requirement of Allen operators for complete temporal knowledge goes against the monotonic knowledge generation sequence, which is witnessed in observation driven fields like stratigraphy. In such cases, incomplete temporal information yields a disjunctive set of Allen operators, which affects RDF reasoning since it leads to expensive queries containing unions. To address this deficiency, we introduce a set of basic temporal primitives, which comprise the minimum possible and yet sufficient temporal knowledge, between associated time intervals. This flexible representation can describe any Allen operator as well as scenarios with further temporal generalization using logical conjunctions. Furthermore, an extension to the basic set of primitives is proposed, introducing primitives of improper inequality, which describe scenarios with increased imprecision that reflect disjunctive temporal topologies. Finally, the proposed temporal primitives are employed in an extension of CIDOC CRM.