Relation Algebras
This section describes the Relation Algebra format and usage found in qualreas.
- Allen’s Algebra of Proper Time Intervals
- Extended Interval Algebras
- References
- Dependencies
- 1. Linear Interval and Point Algebra
- 2. Right-Branching Interval and Point Algebra
- 3. Left-Branching Interval and Point Algebra
- Pick one of the algebras to use for examples
- Algebra Element Summary
- Equality Relations
- Creating Relation Sets
- Operations on Relation Sets
- Global Properties of an Algebra of Relations
- Time Point Algebras
- Reasoning with Relation Algebras: Subalgebras, Consistency, and Tractability
- A Primer for the Notebook, Subalgebras of Allen’s Algebra
- Table of Contents
- Setting Up
- 1. RelSets, Disjunctions and Conjunctions
- 2. The Three Operations: Intersection, Converse, Composition
- 3. Subalgebras, Closure, and Generators
- 4. Intervals Are Made of Points: Convex, Pointisable and ORD-Horn RelSets
- 5. Consistency and Inconsistency
- 6. Path Consistency, and Networks that are Path Consistent but Inconsistent
- 7. Complexity: Decidability, NP-hard, NP-complete, Tractable, Maximal
- 8. Searching for Tractable Subalgebras: Refuted Subalgebras
- Glossary
- Exercises
- References
- Subalgebras of Allen’s Algebra Defined by Point Relations