- In mathematics, an expression or mathematical expression is a finite combination of symbols that is well-formed according to rules that depend on the context. Mathematical symbols can designate numbers (constants), variables, operations, functions, brackets, punctuation, and grouping to help determine order of operations and other aspects of logical syntax.
- Daniel J. Boorstin (Wikipedia)
Daniel Joseph Boorstin (October 1, 1914 – February 28, 2004) was an American historian at the University of Chicago who wrote on many topics in American and world history. He was appointed the twelfth Librarian of the United States Congress in 1975 and served until 1987. He was instrumental in the creation of the Center for the Book at the Library of Congress.