In mathematics, the Iverson bracket, named after Kenneth E. Iverson, is defined as follows History Main article: History of mathematics In addition to recognizing how to count concrete objects, prehistoric peoples also recognized how to count abstract quantities, like time -- days, seasons, years. ... Kenneth E. Iverson (17 December 1920, Camrose, Alberta/Canada –October 19, 2004,Toronto, Ontario/Canada) was a computer scientist most notable for developing the APL programming language. ...

where P is a proposition. In modern philosophy, logic and linguistics, a proposition is the meaning of a sentence, rather than the sentence itself. ...

For example, the Kronecker delta notation is a specific case of Iverson notation, that is, In mathematics, the Kronecker delta or Kroneckers delta, named after Leopold Kronecker (1823-1891), is a function of two variables, usually integers, which is 1 if they are equal, and 0 otherwise. ...

The notation is useful especially in simplifying sums or integrals, for example

as where i is strictly less than 0 or strictly greater than 10, the summand is 0, contributing nothing to the sum. Such use of the Iverson bracket can permit easier manipulation of these expressions.

See also: Indicator function. In the mathematical subfield of set theory, the indicator function is a function defined on a set X which is used to indicate membership of an element in a subset A of X. Remark. ...