Notation3
Notation3 (N3) is a human-readable, compact, and expressive knowledge representation language. It is primarily designed as a superset of Turtle (Terse RDF Triple Language) and intended to be a more general and powerful syntax for representing RDF (Resource Description Framework) data and rules. N3 aims to provide a simpler and more intuitive way to express logical statements and perform reasoning on RDF graphs.
Key features of Notation3 include:
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Rules: N3 allows for the expression of logical rules using the
=>operator to indicate inference. These rules define relationships between different parts of the knowledge graph, enabling reasoning and deduction. -
Generalized Quantifiers: N3 provides universal and existential quantifiers using
@forAlland@forSome, respectively. These quantifiers allow for making statements about groups of resources, improving the expressiveness of the language. -
Formulae as Resources: N3 treats formulae (logical statements) as resources themselves, allowing them to be reified and used in other statements. This meta-modeling capability is crucial for advanced reasoning tasks.
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Built-in Functions and Predicates: N3 includes built-in functions and predicates for performing operations like string manipulation, mathematical calculations, and comparisons. These features enhance the ability to process and transform data within the knowledge graph.
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Compatibility with RDF: N3 is designed to be largely compatible with RDF, meaning that most RDF data can be directly represented in N3. It builds upon the RDF model by adding more expressive features.
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Contexts: N3 uses the
@prefixand@basedirectives, similar to Turtle, to define namespaces and base URIs for compact representation of URIs. These directives allow for brevity and clarity in representing RDF data.
N3 has been used in various applications, including semantic web development, knowledge representation, and rule-based reasoning systems. While its complexity can be a barrier to entry for some, its expressive power makes it a valuable tool for sophisticated knowledge engineering tasks.