Keyphrases
- relation algebra
- semantic web
- semantic relations
- algebraic structure
- relational data model
- real numbers
- maximal tractable
- query language
- semantic web technologies
- conceptual structures
- ontology learning
- semantic web data
- ontological concepts
- algebraic operations
- relational algebra
- linked data
- background knowledge
- data model
- database
- semantic technologies
- temporal relations
- semantically annotated
- algebraic structures
- algebraic expressions
- knowledge base