# Glossary

## Index

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# N

## Node

### Context

A term used in graph theory.

### Definition

A node is an entity in a graph which is connected to zero or more other nodes by zero or more arcs. The nodes of a graph denote the entities we are interested in, while the arcs denote the structural relationships (connections) between them.

### In CG theory

In conceptual graph-theory, the nodes are of two types:

### Other examples

Other examples of nodes include:

• The cities in a graph denoting a map of roads (the roads are the arcs).
• The intersections of roads in a graph representing the map of a city (the roads are the arcs).
• The hosts (servers and clients) in a graph denoting a computer network, such as the internet (the network links between them are the arcs).
• The constituents in a phrase-structure-tree representing a sentence, such as "NP", "VP", "S", "PP", etc. (The lines between the constituents are the arcs).
• The types in a type hierarchy-lattice (the "subtype relation" links are the arcs).

## Numeric constant

### Context

A term in Prolog.

### Definition

A numeric constant is simply a number. It must either be an integer or a real number. A real number can be taken in this context to be a number with a decimal fraction.

### Examples

For example, the following are all numeric constants:

• 1
• 5
• 42
• 3.14
• 72.5
• 1995.95

The first three are integers, while the last three are real numbers.

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