The last president who ever owned slaves was, ironically, Ulysses S. Grant, elected in 1868 after he had commanded Union forces to victory over the Confederacy in the war that led to the abolition of slavery. Grant owned a slave named William Jones, whom he freed in 1859.
AI and Linux enthusiast. In general, a namespace is a container for a set of identifiers (also known as symbols, names). Namespaces provide a level of direction to specific identifiers, thus making it possible to distinguish between identifiers with the same exact name. For example, a surname could be thought of as a namespace that makes it possible to distinguish people who have the same given name.
As defined by the W3C Namespaces in XML Recommendation, an XML namespace is a collection of XML elements and attributes identified by an Internationalized Resource Identifier (IRI); this collection is often referred to as an XML vocabulary..ML Schema is used to create a vocabulary for an XML instance, and uses namespaces heavily. Thus, having a sound grasp of the namespace concept is essential for understanding XML Schema and instance validation overall.